Att v11issue2 2017

ASTRONOMY

TECHNOLOGY TODAY Your Complete Guide to Astronomical Equipment TELE VUE AND AL NAGLER • WHAT ARE SOLAR ECLIPSE GLASSES MADE OF? DESIGNING AND CONSTRUCTING A 28-INCH F/3.6 DOB • CELESTRON LITHIUM POWERTANK DIY DEW HEATERS • LOOKING BACK SERIES: THE ASTRO HUTECH HINODE • OBSERVING THE SUN IN COLOR WITH THE MALLINCAN XTREME

The

Stellarvue SV70T Everything It’s Advertised to Be!

Volume 11 • Issue 2 $6.00 US

Contents

Cover Story: Pages 41-44 Our cover features Stellarvue’s SV70T, a mechanically and optically excellent f/6, 70-mm apochromatic refractor that is highly portable and punches well above its weight in both visual and astrophotography performance. Dr. James R. Dire shares his impressions of the compact refractor in this issue. He also captured the background two-hour exposure of the Horsehead and Flame nebulae region using the SV70T.

In This Issue 8

EDITOR’S NOTE Star Parties

by Gary Parkerson

31 THE STELLARVUE SV70T Everything It’s Advertised to Be!

By Dr. James R. Dire 39 DESIGNING AND CONSTRUCTING A 28-INCH F/3.6 DOB Part 1 - Lessons Learned

By Tony Bryan 51 WHAT ARE SOLAR ECLIPSE GLASSES MADE OF? And Why We Don’t Use a Polarization Filter

By Eric Gentry 55 TELE VUE AND AL NAGLER Celebrating 40 Years of Innovation

By Gary Parkerson

ASTRONOMY

TECHNOLOGY TODAY Your Complete Guide to Astronomical Equipment TELE VUE AND AL NAGLER • WHAT ARE SOLAR ECLIPSE GLASSES MADE OF? DESIGNING AND CONSTRUCTING A 28-INCH F/3.6 DOB • CELESTRON LITHIUM POWERTANK DIY DEW HEATERS • LOOKING BACK SERIES: THE ASTRO HUTECH HINODE • OBSERVING THE SUN IN COLOR WITH THE MALLINCAN XTREME

Industry News/New Products 10 TELE VUE DeLite Focal Lengths of 13-mm, 4-mm, and 3-mm Now Available

The

Stellarvue SV70T Everything It’s Advertised to Be!

10 CHRISTIAN LEGRAND AND PATRICK CHEVALLEY Virtual Planets Atlas Version 2

In This Issue

Volume 11 • Issue 1 $6.00 US

71 CELESTRON LITHIUM POWERTANK The evolution of the lead-acid and lithium-ion battery finally adds convenience to the revolution of affordable go-to mounts.

By George Stallings Observing the Sun in Color with the MallinCam Xtreme

By Cliff De Lacy 81 THE ASTRO HUTECH HINODE SOLAR GUIDER The Hinode Solar Guider is surely a tool you need to check out.

By Austin Grant

12 INCANUS Releases Major Updates to Astro Photography Tool (APT)

14 AIRYLAB Adds New Autofocus Feature for Imaging in Genika 2.13

16 REVOLUTION IMAGER Hosts Monthly Imaging Contest

61 DYI DEW HEATERS A Step by Step Guide

By Charles Jagow

Astronomy TECHNOLOGY TODAY

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Contributing Writers Tony Bryan is an amateur astronomer, living in Jasper, Indiana and a member of the Evansville Astronomical Society (EAS), based in Evansville, Indiana with observatory facilities located in Lynnville, Indiana. He is currently serving as President of the EAS. Tony loves tinkering and is experienced in woodworking, car restoration, and electronics. His past ATM projects include: design and construction of an electronic telescope/camera clock drive, design and construction of portable power systems, design and construction of a roll-off-roof observatory, design and construction of various camera and telescope mount accessories, rebuild and electronics retrofit on a 16-inch Dobsonian, and rebuilding of several telescope drive systems.

Cliff De Lacy retired from the Defense Department after 35 years. He has a Master in HR Management and has taught Nuclear Physics/Radiological Control Fundamentals. A credentialed teacher, he also taught astronomy for the Napa Valley College for Kids Program and is currently a guest teacher in local school districts. He was appointed by JPL in 2003 as a Volunteer Solar System Ambassador for Outreach on NASA missions and enjoys conducting corporate and private star gazing sessions in Northern California . You can read about his outreach efforts at www.thestarguide.com.

Dr. James Dire has an M.S. degree in physics from the University of Central Florida and M.A.and Ph.D. degrees from The Johns Hopkins University, both in planetary science. He has been a professor of physics astronomy at several colleges and universities. Currently he is the Vice Chancellor for Academic Affairs at Kauai Community College in Hawaii. He has played a key role in several observatory projects including the Powell Observatory in Louisburg, KS,which houses a 30-inch (0.75-m) Newtonian; the Naval Academy observatory with an 8-inch (0.20-m) Alvin Clark refractor; and he built the Coast Guard Academy Astronomical Observatory in Stonington, CT, which houses a 20 inch (0.51-m) Ritchey–Chrétien Cassegrain telescope.

Contents

Industry News/New Products 18 SIMULATION CURRICULUM Creates New Forums for SkySafari Users

20 AGILE AUTOGUIDER An iPhone App for Telescope Guiding

20 ASTRONOMIK Clip-Filters for Canon EOS M Now Available

Eric Gentry is an astrophysics graduate student at UC Santa Cruz, studying the intersection of computation and physics. As an undergrad at MIT, he used the Hubble Space Telescope to study the most energetic processes in the universe (AGN). HE also helped build experimental X-ray telescopes and devices, and worked with an international collaboration to track how greenhouse gases move through our atmosphere.

Austin Grant, a high-school Chemistry and Biology teacher, is a self-described perpetual hobbyist, experienced in such areas as building computers and repairing arcade equipment. Austin stumbled into astronomy several years ago and it soon became his primary interest. Being a child of the digital age, it didn’t take long for him to find digital astro-imaging and he sold his last pinball machine to fund his current imaging rig.

Austin shares his passion for stargazing with his students.

Chuck Jagow serves as the President of the Back Bay Amateur Astronomers which is an astronomy club in South Eastern Virginia dedicated to bringing astronomy to the public. He lives in Chesapeake and is an IT professional for the Department of Defense and an ex-submariner. Chuck’s initial interest in astronomy began while growing up in the Sangre De Cristo mountains of Colorado and was rekindled after a 30+ year hiatus by his wife giving him a 70mm go-to scope for Christmas almost 12 years ago. His greatest passion is astronomy outreach and dabbling in astro-imaging.

Gary Parkerson discovered early in his amateur-astronomy career that he was as fascinated by the tools of astronomy as by the amazing celestial objects they reveal – perhaps more so. When not writing about astro-tech, he covers industrial technology for a variety of online resources.

George Stallings has been observing for more than 25 years, though he has only recently jumped into the world of lunar and planetary imaging. A career information analyst and lifelong science-hobbies enthusiast, he navigates the fine line between late nights imaging and early mornings consulting for the federal government in northern Virginia.

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Astronomy TECHNOLOGY TODAY

22 WILLIAM OPTICS Twentieth Anniversary Limited Edition Telescopes

24 CCD-GUIDE 2017 Edition Now Available

26 LISTEN TO THE STARS Messier Objects Audio Book and Sketch/Reference Book

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ASTRONOMY

TECHNOLOGY TODAY

Volume 11 • Issue 2 Publisher

Editor’s Note Gary Parkerson, Managing Editor

Stuart Parkerson

Managing Editor Gary Parkerson

Associate Editors Austin Grant Sean Melehan Chad E. Patterson Logan Parkerson

Art Director Lance Palmer

Web Master Richard Harris

3825 Gilbert Drive Shreveport, Louisiana 71104 info@astronomytechnologytoday.com www.astronomytechnologytoday.com Astronomy Technology Today is published bi-monthly

by Parkerson Publishing, LLC. Bulk rate postage paid at Dallas, Texas, and additional mailing offices. ©2012 Parkerson Publishing, LLC, all rights reserved. No part of this publication or its Web site may be reproduced without written permission of Parkerson Publishing, LLC. Astronomy Technology Today assumes no responsibility for the content of the articles, advertisements, or messages reproduced therein, and makes no representation or warranty whatsoever as to the completeness, accuracy, currency, or adequacy of any facts, views, opinions, statements, and recommendations it reproduces. Reference to any product, process, publication, or service of any third party by trade name, trademark, manufacturer, or otherwise does not constitute or imply the endorsement or recommendation of Astronomy Technology Today. The publication welcomes and encourages contributions; however is not responsible for the return of manuscripts and photographs. The publication, at the sole discretion of the publisher, reserves the right to accept or reject any advertising or contributions. For more information contact the publisher at Astronomy Technology Today, 3825 Gilbert Drive, Shreveport, Louisiana 71104, or e-mail at info@astronomytechnologytoday.com.

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Astronomy TECHNOLOGY TODAY

STAR PARTIES has a temporarily-negative effect on visual acuity and …” until, like Wiley Coyote wondering why the anvil was getting bigger, it hit me: It was the word “party” that caused her to wonder. She’d been invited to a party, and when a guest at parties, she was accustomed to contributing refreshments. I had been so thoroughly immersed in astronomy for so long, I’d completely lost touch with the potential expectations of From left to right: Marcia Ray, Jan Gallaway, Sheryon Pilgrim star-party newbies. and Sheila D’Alo. Google tells me that “party” means “a social gathering of invited guests, I’m in the Florida Keys as I write this, typically involving eating, drinking, and enterpreparing to start the East Coast leg of the tainment.” Well, there you go. It also lists “celePedaling Astronomer Project with a first goal of bration” as a synonym, and WSP is certainly a pedaling from Florida to New York in time for celebration, albeit a peculiarly focused one.

NEAF 2017. Of course, for über astronomy I don’t know the origin of the term, “star enthusiasts, February in the Keys means the party,” but if you have a theory, please share it.

Winter Star Party, to which I was accompanied Wikipedia includes a page that suggests the idea this year by four young ladies for whom WSP of star parties may date back to King George III, represented their maiden star-party voyage. I was who was also an avid amateur astronomer, but it there for just one evening to report on the event, does not make a guess as to who first called a star and they were there to take photos and gather party that. Wikipedia also lists notable star parimpressions from their unique newcomer perties, and mentions WSP first, followed by the spectives.

Mid Atlantic Star Party, the Oregon Star Party, And what an enviable first-star-party experithe Stellafane Convention and the Texas Star ence! As fate would have it, it was the clearest Party. Yes, that list excludes more than one biggie night of observation of the past seven years, – like Okie-Tex – but it’s still quite an amateurbut even on average nights, WSP is considered astronomer bucket list, no? by most a premier star party, if not the premier The homepage of WSP introduces it with star party. Of course, all Southern Cross the sentence, “The Winter Star Party is a serious Astronomical Society volunteers were, as always, event designed for amateur astronomers.” A seriwelcoming and gracious, not to mention compeous party? No wonder my friend misunderstood. tent, but we owe a special thanks to Charles Quoting Google again, serious means “demandPerillo. ing careful consideration or application … acting Anyway, in anticipation of our evening at or speaking sincerely and in earnest, rather than WSP, one of the ladies asked, “Should we bring in a joking or halfhearted manner.” anything?” My puzzlement must have been obviYes, there is an aspect of seriousness to star ous, because she continued, “You know, like food parties. Participants are respectful of neighbors or beer or wine?” I stammered something to the and share a quiet sense of reverence for astronoeffect, “I don’t know whether anyone brings alcomy, along with views through their telescopes. holic beverages to WSP, or to any other weekThey do indeed speak “sincerely and in earnest,” long star party, for that matter, because alcohol and their voices are rarely raised above awestruck

oohs and ahhs, although a passage of the International Space Station or the flare of an Iridium satellite might be greeted with spontaneous applause. Afterward, one of my guests described her inaugural WSP experience as “immersion in reverent gentleness.” I’d never thought of star parties in that light, but yes, her description now feels especially apt.

But the only context in which I’d likely use the adjective “serious” to describe WSP is that of serious fun. If a warm week-long break from winter wasn’t enough, it’s astronomy under steady skies, to boot! For avid astronomy enthusiasts, what other annual venue could promise more?

My four guests spent much of the night with Greg Bragg of Explore Scientific and one of that company’s new 16-inch Truss-Tube Dobsonians (designated DOB1545-00). There were many larger Dobs at WSP, but none guided by a host more at ease in the context of public outreach. He introduced the ladies to one spectacular highlight object after another – including M42, M45, M51, M81 and 82, the Double Cluster, and of course, oh-so-grand Jupiter – and narrated each target with the easy banter of one who is not only intimately familiar the night sky, but who also loves it.

That 16-inch f/4.5 is such a sweet setup – big enough aperture for going intriguingly deep, but of short enough focal length for feet-onground viewing, yet also slow enough that a coma corrector is a nice option rather than an absolute viewing necessity. I’ve long debated whether the ideal light bucket is an f/4.5-ish 16or 18-incher, but with major components weighing a relatively-light 22 pounds (10 kilograms) and 66 pounds (30 kilograms), I’m really liking these 16-inch Dobs.

Greg closed the extensive viewing session with a personal anecdote about the instant transformation of a teen who approached his first view of Saturn with a marked affectation of disinterest.

The ladies who have yet to view that show-stealing planet undoubtedly will before many more new Moons.

WSP is unique and a must-have amateurastronomer experience, but then every major star party is. I spent the last weekend in January at the Death Valley Winter Star party, and it too is like no other I’d previously enjoyed. But more on that in a future column.

Oh, and by the way, when the night was over, my guests assured me that the views through Greg’s telescope would not have benefitted from the enhancement of alcohol. Not in the least.

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NEWPRODUCTS/INDUSTRYNEWS

TELE VUE DeLite Focal Lengths of 13-mm, 4-mm, and 3-mm Now Available Tele Vue has announced the newest DeLite focal lengths are now available. Rounding out the series are focal lengths of 13-mm, 4-mm, and 3-mm. These new DeLites are parfocal with the current 18.2mm, 15-mm, 11-mm, 9-mm, 7-mm, and 5-mm models.

The DeLite 62-degree apparent field eyepieces were developed based on Tele Vue’s Ethos eyepiece design advancements, as were the Delos eyepieces, and offer a smaller, more economical and lightweight version of Delos.

All models have 1.25-inch barrels, offer 20-mm eye-relief and are parfocal with Tele Vue's 1.25-inch Plössl, Panoptic, Nagler, and Delos eyepieces. The DeLite is designed to handle the Tele Vue Dioptix astigmatism compensator. Each eyepiece is extremely lightweight, offers an ultra-slim profile and provides a unique sliding/locking eyeguard.

The eyepiece line is named DeLite, because that is how Tele Vue describes the viewing experience. The name also recognizes Tele Vue designer Paul Dellechiaie’s work.

Please visit www.televue.com website for more information.

CHRISTIAN LEGRAND AND PATRICK CHEVALLEY Virtual Planets Atlas Version 2 Virtual Planets Atlas Version 2 (VPA Pro 2.0) is the second release since the software’s introduction in 2013. The tool allows users to study topographic and scientific data for planets and satellites surfaces. It is published by Christian Legrand, a lunar observer, and co-author of the guide "Discover the Moon" by Cambridge University Press and Patrick Chevalley, author of the planetarium software Cartes du Ciel. The duo is the same team who publishes the Virtual Moon Atlas software which offers a database with more than 60 000 entries of topographic and scientific data of the Moon’s near side and far side.

The Virtual Planets Atlas offers data as it becomes available for telluric planets and Solar System satellites. The data is made available from the fleet of performing probes sent by the various space agencies (USA, Europe and others). The release of version 1 included Mercury, Venus and Mars. New for Version 2 is the addition of Jupiter and its four Galilean satellites.

With VPA Pro 2.0, the authors have

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Astronomy TECHNOLOGY TODAY

integrated the latest data available from the International Astronomical Union (IAU) for Mercury, Venus, Mars, Io, Europa, Ganymede and Callisto. For Jupiter, they created a special database that includes all the available information about zones and belts. Additionally, there are now 401 named formations for Mercury; 2033

named formations for Venus; 1797 named formations for Mars; 227 named formations for Io; 112 named formations for Europa; 190 named formations for Ganymede and 154 named formations for Callisto.

VPA Pro 2.0 is available as a free download for Windows, Linux and MacOs at http://www.ap-i.net/avp/en/start.

NEWPRODUCTS/INDUSTRYNEWS

INCANUS Releases Major Updates to Astro Photography Tool (APT) First introduced in 2009, APT stands for “Astro Photography Tool” and is the brainchild of Ivo Stoynov, who calls the software a “Swiss army knife for your astro imaging sessions.” The software draws upon the knowledge of many astro photographers from all over the world, as well as from the author’s own experience.

No matter what camera you use – Canon EOS DSLR or CCD – APT has the right tool for planning, collimating, aligning, focusing, framing, controlling, imaging, synchronizing, analyzing and monitoring. All features are packed in an

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Astronomy TECHNOLOGY TODAY

easy and comfortable to use interface. Ivo continues to improve and refine APT and packs new features in every major release. Currently, APT works on MS Windows XP, 7, 8, 8.1 and 10.

APT provides support for: • Five generations of Canon EOS Models.

• ASCOM compatible CCD cameras – QHYCCD, Starlight Xpress, Atik, Orion, Moravian and more.

• Native support for QSI cameras and filter wheels.

• Native support for SBIG cameras and filter wheels.

• TEMPer(Gold) and TEMPerHUM sensors.

• USB Dewpoint sensor.

• Any serial control cable.

• Shoestring Astronomy DSUSB/ DSUSB2 and Biula Audio Trigger.

• ASCOM compatible filter wheels.

• ASCOM compatible focusers.

• ASCOM filter wheel to focuser connection to apply filter focus offsets.

• ASCOM compatible rotators.

• ASCOM telescopes control.

• Extended support for AstroHub and SirJolo Arduino based focusers.

• Direct dithering (APT Dithering), when there is no guiding program.

• Direct pulse dithering (APT Pulse Dithering) for self-guided solutions.

• Unihedron and compatible Sky Quality Meter devices.

APT has a dedicated forum – www.aptforum.com – where you can ask or search specific questions. The forum also offers a growing source of information related to astro-photography, including imaging, automation, processing and more. To learn more about this latest release, visit www.astroplace.net.

NEWPRODUCTS/INDUSTRYNEWS

AIRYLAB Adds New Autofocus Feature for Imaging in Genika 2.13 AiryLab’s Genika Astro is an imageacquisition software dedicated to astronomical imaging. It supports high-speed cameras, including those from Andor, AVT, Basler, IDS, PointGrey, Raptor Photonics, Celestron, The Imaging Source and ZWO. The company has announced two recent releases that significantly augment the functionality of the software.

Genika Astro offers enhanced performance for direct image-to-disk recording. It can sustain more than 400MB/s throughput for long periods of time – the only limit being the disk capacity. It uses the advanced data management of its sister application, Genika Trigger, to minimize the frame loss – or even eliminate it – by using the FIFO dynamic buffering and two leaky-bucket algorithms.

Stringent timing requirements are covered either using GPS resynchronization, for a precision better than 10ms, or using the optional UTC Timebox that controls the camera shutter directly for a sub millisecond precision.

Designed for both professional and enthusiast astronomers, it brings a unique

feature set that covers all applications for short exposure imaging, including (1) highspeed image recording for imaging of planets, the Moon and Sun and star occultations by asteroids with support of low-noise EMCCD cameras, (2) mutual phenomena between the moons of the giant planets for photometric analysis, (3) any image acquisition that requires a highprecision timestamping, (4) automated high-resolution solar acquisition when used with Airy Lab’s Solar Scintillation Monitor, and (5) image acquisition based upon an external trigger.

With the release of Genika 2.13, Airy Lab has introduced a new scoring for the focus of the video stream with a low sensitivity to turbulence – providing real autofocus implemented in a high-speed astronomy acquisition software. It can be used manually to achieve target image sharpness values or more precise real autofocus when an absolute ASCOM focuser is connected (in which Genika tests the sharpness across

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the focus range and performs a Gaussian fit to determine the best focus position). This method is very accurate, even with turbulence and high digital sampling.

With Genika 2.13.2.0, it is possible to integrate your own image processing library.

Genika can call two external DLL files – one for images to be displayed and the other for all images acquired. Two Visual Studio 2015 C# templates, with examples, are provided. Those DLL files are instanciated and you can use you own windows, methods, members and threads. You can return to Genika a modified image, and/or just copy it to make you own processing using any language and any image processing library.

You can learn more at www.airylab.com.

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Astronomy TECHNOLOGY TODAY

NEWPRODUCTS/INDUSTRYNEWS

REVOLUTION IMAGER Hosts Monthly Imaging Contest Revolution Imager is hosting a monthly imaging contest with the winner receiving their choice of any Revolution Imager accessory valued at $100 or less, with free shipping included anywhere in the USA and or discounted shipping anywhere in the world. Each month, entries must be emailed into to the company at

least five days before the end of the month. All entries must be images captured with a Revolution Imager.

January’s winning entry was from Misel Rakic of Germanym, with his image of the Great Orion Nebula shown here. To submit your entry, visit www.revolutionimager.com.

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Astronomy TECHNOLOGY TODAY

NEWPRODUCTS/INDUSTRYNEWS

SIMULATION CURRICULUM Creates New Forums for SkySafari Users Since its introduction in 2009, Simulation Curriculumâ&#x20AC;&#x2122;s SkySafari has grown to be one of the most popular and heavily used astronomy programs in the world. Of course, with this type of audience for a software application, there are also a lot of questions users have on maximizing the power of the program.

As many companies have found, Yahoo groups have limitations in searchability and scale as user communities expand. For SkySafari, the answer was to create an in-house forum option using ZenDesk, which provided the ability to be customized specifically for their user community.

One benefit of the new forum is that SkySafari developers will be

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Astronomy TECHNOLOGY TODAY

closely monitoring the forums and will be available to answer your questions. Taking things a step further, the forums are tied in with the companyâ&#x20AC;&#x2122;s ZenDesk customer support ticket system, so if they believe a question or discussion warrants being taken private as a support ticket, they

can easily do so. The forums are also tied into the SkySafari knowledge base and the entire forum is searchable to quickly get to the most relevant content.

You can learn more by visiting website at https://support.simulationcurriculum.com.

NEWPRODUCTS/INDUSTRYNEWS

AGILE AUTOGUIDER An iPhone App for Telescope Guiding First released in the Apple App Store December 2016, the Agile Autoguider is an iPhone app that corrects the mechanical guiding of your telescope to achieve high guiding precision. The iPhone is attached to the finder scope of your telescope and tracks a guide star via the rear camera. If the guide star drifts, an actuation is computed to bring the telescope back to position. Continuous corrections enable you to take long-exposure photos with dot-shape stars or to train the periodic-error correction of your telescope mount.

The program supports autoguiding via WiFi adapter and manual guiding with on-screen instructions. The setup is straightforward – attach the iPhone to your finderscope, calibrate, and start guiding. You’ll need an adapter to attach your iPhone (running iOS 8.0 or later) to your scope. The app offers a wide range of settings with comprehensible descriptions for optimal guiding performance.

The app provides two kinds of guid-

ing: manual and automatic. When guiding manually, the app tracks the guide star and gives you advice on how to move the telescope to keep the guide star in position. When guiding automatically, the app is connected directly to your mount. If the guide star deviates from its position, the app controls the mount so that the star appears at the original position again.

A typical setup, shown in the accompanying image, consists of a finder scope with T2 connection, an adapter for eyepiece photography with inserted wide-angle (25-mm) eyepiece, a T2 extender; a smartphone-to-T2 adapter, an iPhone 5 communicating to a SkyFi Wireless Telescope Controller and a DSLR in focuser of telescope. Adding a 90-degree angle prism makes interaction with the smartphone more convenient, especially if you use a Newtonian telescope.

The app is the brainchild of Malte Weiss, PhD. You can learn more at www.malte-weiss.de/agileautoguider/ .

ASTRONOMIK Clip-Filters for Canon EOS M Now Available

Astronomik's Gerd Neuman has announced that the company’s the new Clip-Filters for the Canon EOS M series

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Astronomy TECHNOLOGY TODAY

are now available.

The filters are optimized to be used with normal lenses, as well as with a telescope. They can even be used with Canon’s ubiquitous EFM 18-55mm IS lens.

With the EF-M to EF adapter from Canon, all Canon lenses and all lenses from other manufacturers can be used.

The filters can be used with Canon EOS M1 and M3 bodies, including when mated to standard Canon EF lenses when using the Canon

adapter from EF-M to EF. There will also be a special version of the filter for Canon’s EF-M 11-22 Wide Angle Zoom Lens, which provides pinpoint stars to the edge of the field.

Available Astronomik EOS M Clip Filters include: CLS Clip-Filter; CLS CCD Clip-Filter; UHC Clip-Filter; UHC-E Clip-Filter; ProPlanet 642 BP Clip-Filter; ProPlanet 742 Clip-Filter; ProPlanet 807 Clip-Filter; OWB Type 3 Clip-Filter; H-alpha 6nm CCD ClipFilter; H-alpha 12nm CCD Clip-Filter; OIII 12nm CCD Clip-Filter; and SII 12nm CCD Clip-Filter.

Please visit www.astronomik.com for more information.

with “T TAKUMI” AKUMI” Spirit

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NEWPRODUCTS/INDUSTRYNEWS

WILLIAM OPTICS Twentieth Anniversary Limited Edition Telescopes William Optics is offering several limited-edition telescopes as the company continues its 20th anniversary celebration. These are very limited, and when they are gone there will be no more, so if you see one that fits your eye and budget don’t hesitate to grab yours!

ZenithStar 71mm f/5.9 Doublet ED Refractor - 20th Anniversary Limited Edition The ZenithStar 71 ED Doublet is a small-aperture, extremely-portable ED scope that offers excellent mechanics, fit and finish. It comes with the latest WO 2-inch rack-and-pinion two-speed fine focuser that replicates the smoothness and lack of backlash normally associated with a Crayford focuser, with the advantage of increased mechanical strength. It can be fully locked and will not flex or slip even with a heavy camera combination.

The telescope offers Japanese imported Ohara ED glass in an air-spaced doublet arrangement in a CNC machined ultra-high precision lens cell. Each lens is fully multi-coated with a special superhigh transmission coating (STM Coating) on all surfaces. The telescope is fully baffled to block all extraneous offaxis light rays and prevent glancing reflections, increasing overall contrast.

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Astronomy TECHNOLOGY TODAY

The ZenithStar 71 works well with Vixen-style mount dovetail bases as it can be slid directly into the mount without a dovetail plate. The scope offers a powderpainted white CNC-machined aluminum tube finished in red with a drawtube travel length of 80 mm with graduated scale. The retractable dewshield is WO’s smallest size ever, offering enhanced portability. The telescope comes with a free soft carry back and is retail priced at $598US. GT71 71mm f/5.9 Apo Refractor 20th Anniversary Limited Edition The GT71 Apo features a three-element objective using high-quality FPL53 extra-low dispersion glass that greatly reduces any secondary spectrum. It offers high-end fit and finish with its powderpainted white CNC-machined aluminum tube, gold trim finish, retractable dewshield, and dewshield cap.

The telescope comes with an extrasmooth 360 degree rotatable 2-inch rack -and-pinion V-Power Focuser with 1:10 dual speed eliminating image shifting during astrophotography. The focuser has stainless-steel reinforcement inserts on both sides and on the back to facilitate heavy loading. It comes with two locking screws on angled positions for heavy load applications as well as an aluminum knob

with installed thermometer.

The telescope is retail priced at $798US. GT81 81mm f/5.9 Apo Refractor w/ Field Flattener - 20th Anniversary Limited Edition Offering superb quality for imaging and visual use, this is a compact scope that is well suited for travel and you’ll enjoy showing it off as much as using it as the powder-painted white CNCmachined aluminum tube with its gold trim finish is visually stunning.

The GT81 Triplet is a three-element super apo, which offers an air-spaced objective (FPL-53) in an adjustable CNC machined, ultra-high precision lens cell.

Providing extremely sharp views with excellent color correction, each lens is fully multi-coated with STM Coating on all surfaces.

It comes with an extra-smooth 360 degree rotatable 2-inch rack and pinion focuser with 1:10 dual speed. It also comes with two locking screws on angled positions for heavy load applications; a large aluminum knob with installed thermometer; a graduated scale for precise camera alignment on focuser tube; top mounted 50-mm finder bracket; 2-inch and 1.25-inch adapter and a L-bracket Vixen/Synta-style dovetail base. The sug-

NEWPRODUCTS/INDUSTRYNEWS gested retail price is $1,058US. GT102 102mm f/6.9 Apo Refractor 20th Anniversary Limited Edition The William Optics GT 102 Apo is presented in a pristine white finish CNCmachined aluminum tube with blue or gold trim. The GT 102 features a three-

element objective using high-quality FPL-53 glass combined with other extralow dispersion glass that reduces to a high degree any secondary spectrum. Each lens is fully multi-coated with STM Coating on all surfaces.

The package includes tube mounting rings; retractable dew shield and dew-

shield cap; 3-inch Victory Edition Crayford design with 360-degree rotatable focuser; two-speed knobs â&#x20AC;&#x201C; 1:10; 2inch and 1.25-inch adapters; Vixen style dovetail plate and soft carry case.

The GT 102 APO weighs 11 pounds and is 27 inches in long. The suggested retail price is $2,398US.

Image 1 - ZenithStar 71mm f/5.9 Doublet ED Refractor 20th Anniversary Limited Edition

Image 3 - GT81 81mm f/5.9 Apo Refractor w/ Field Flattener - 20th Anniversary Limited Edition

Image 2 - GT71 71mm f/5.9 Apo Refractor - 20th Anniversary

Image 4 - GT102 102mm f/6.9 Apo Refractor - 20th Anniversary Limited Edition

Astronomy TECHNOLOGY TODAY

23

NEWPRODUCTS/INDUSTRYNEWS

CCD-GUIDE 2017 Edition Now Available The CCD-Guide is a project of Astronomischer Arbeitskreis Salzkammer-gut (AAS) – Gahberg Observatory (www.astronomie.at) in Austria. Every year since 1997, the CCD team of the Gahberg observatory publishes a new DVD that contains the best CCD and DSLR images of the AAS members. The total revenue from the sale of the DVD is used to assist the association and AAS projects.

The CCD-Guide is designed to assist astrophotographers in planning their imaging projects. Besides a huge number of reference images, the CCD-Guide contains software to find images, to view images and to obtain all necessary data. The newest release contains more than 3,700 reference images, plus 1,500 archive images of 53 astrophotographers.

The CCD-Guide includes an extensive deep-sky object database, including object data, based on 30 big standard catalogues. It provides easy search functionality for objects with simultaneous viewing of object data, image acquisition data and preview picture. Users can filter the images by different criteria, such as coordinates, object type, object size, constellation, catalogue, observer, camera, telescope or date. Users can create a slide show of selected images. You can input your own images including data to create your personal image archive, and there is a planning function for your imaging projects.

The software is lightweight, needing minimal system requirements, and is executable on all current Windows PCs

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Astronomy TECHNOLOGY TODAY

(starting with Windows XP), without installation. You can order the new CCD-Guide 2017 at a price of 29 € + postage.

All users of older CCD-Guide versions can buy an update for the new release 2017 at a price of 19 € + postage. Learn more at www.ccdguide.com.

TELEPHONE 512-259-9778 WEBSITE www.scopestuff.com EMAIL Support@scopestuff.com Scopestuff is your primary source for all of the stuff you need for a great observing experience! Most orders ship the same day and prices include shipping in the USA! Our website includes hundreds of items including: SOLAR OBSERVING STUFF GET READY FOR THE SOLAR ECLIPSE! SOLAR FILTERS, FILTER MATERIAL, SOLAR AND MORE. FILTERS INDIVIDUAL FILTERS, COMPLETE SETS, ADAPTERS, CASES AND MORE! RINGS, RAILS, DOVETAILS, WEIGHTS

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NEWPRODUCTS/INDUSTRYNEWS

LISTEN TO THE STARS Messier Objects Audio Book and Sketch/Reference Book We were recently made aware of JJ Evans’ Listen to the Stars audio book and companion sketch/reference book.

Rarely do we learn of a resource that we find truly different – that is so well positioned to enhance our viewing experiences in such a unique way – but this combo audio and print publication does precisely that.

Listen to The Stars Audio Book The audio book was designed to enhance your binocular or telescope viewing sessions. Just load the files into your favorite audio device (phone, tablet, MP3 player, etc.) and put on your favorite headphones. Then choose

the Messier Object of your choice, and be prepared to be add a new dimension to your viewing experience.

The audio book is an immersive audio experience, which allows you to listen to any or all of the 110 Messier Objects. Listening to the interesting facts/history (and background music) will absorb you into the views ... all while never having to take your eye from those views. Even if you have seen your favorite object numerous times, re-visit-

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Astronomy TECHNOLOGY TODAY

ing them while listening on your preferred audio device can bring new meaning to your view.

Instead of simply reading the history and facts about a Messier Object, you can now listen to them while at the scope. Listen to the narrator as he provides a wealth of interesting facts and history on your object. You will discover that your view will take on a more interesting aspect as he points out the finer details of the object. Previously hidden visible details reveal themselves when observed in concert with verbal descriptions, and the entire experience is further enhanced by the spatial background music.

Let’s say you are viewing Messier 13, the Great Hercules Cluster. You may have seen it before, but now, witness it while listening to the narrator explain: “Many of the outer stars seem to be arranged in long arcs weaving their way across the cluster face, and the distribution of the bright stars is not even across the surface. Also, there are three dark dust lanes that form a Y shape towards the southeast of the core. This is known as the “propeller.”

Whether you are new to astronomy or a seasoned amateur, this audio experience will certainly add a new, deeper perspective to your viewing sessions.

Messier Astronomy Reference & Sketch Book This 294-page book offers an excellent way to combine locating your object and documenting/sketching your findings. It can be used at the scope, or information can be added later at your leisure. It becomes a culmination of facts, history and sketches, which nurtures that creative outlet for your viewing sessions.

The Paper Back Book is a comprehensive Sketch/Facts/History/Listings/

Data Book. An all-in-one-style work book. Even if you don’t enjoy sketching, the book is a great “diary” for your observation sessions.

The sketch pages, which are in Messier order, have space for recording pertinent information such as – Site, Weather, Moon, Scope, Eye Pieces, Magnification, Constellation, Notes, etc. It even has a globe to record the sky area where the object was located.

Accompanying each sketch page are facts and history on the featured Messier object. Other pages include Atlas Info, Charts, Viewing by Season, Constellation, Personal Notes and more.

And when you’re done, you will have a physical history of your viewing experiences that you can share with your family and friends. And maybe, many years from now, one of your relatives will enjoy reliving your favorite pastime.

The Audio Book is for sale on both iTunes and Amazon. The paperback can be purchased on Amazon or directly through the author at his website. More information is available at www.listentothestars.net.

THE STELLARVUE Everything It’s SV70T Advertised to Be!

By Dr. James R. Dire

Editor’s Note: Dr. Dire’s report on the Stellarvue SV70T is a first installment of a two-part series on this popular telescope. Look for additional coverage in our next issue.

I have owned no fewer than four Stellarvue refractors this century; two doublets and two triplets. They all have been superbly crafted instruments. The one I have held onto the longest is my SV102T, a 102-mm f/7.9 triplet Apo. Its 800-mm focal length is a great middle-of-the-road focal-length instrument for viewing the Moon, the planets, star clusters, double stars, and brighter galaxies and nebulae.

The instrument has also proved to be stellar for CCD imaging, with and without my Tele Vue 0.8x focal reducer/field flattener.

Wanting a shorter focal-length refractor for overseas travel and wide-field imaging, I decided to test out Stellarvue’s new SV70T. Some short focal-length apos are optically very fast, f/4.8-f/5. This is accomplished using four to five optical elements inside the telescope, which provide nice flat fields. But for visual use, the focal lengths are too short to achieve very high magnification. The SV70T is a 70mm f/6 apo triplet telescope. It has a 420-mm focal length. I purchased it with the Stellarvue 0.8x focal reducer/field flattener designed specifically for this instrument to convert it into a 336-mm f/4.8 focal-length astrograph. Like my SV102T system, I have the longer focal length for visual use and the shorter focal length for imaging.

Image 1 shows this fabulous instru-

Image 1 - The Stellarvue SV70T telescope mount on the autho’s Orion Atlas mount.

ment. As seen in the image, the telescope comes with a Stellarvue 2.5-inch dualspeed, rack-and-pinion focuser, a short Vixen-style dovetail bar, and heavy-duty tube rings. I already owned the telescope mount, two-inch diagonal, eyepiece and finderscope shown in the image, so I was prepared to use the telescope straight out of the box. This telescope also comes with a padded, airline carry-on-sized travel, soft-

side case with plenty of extra room for the diagonal and a few eyepieces.

The objective is a multi-coated, threeelement lens with an Ohara FPL-53 center element (Image 2). The center element ensures each color of the spectrum is in sharp focus simultaneously. Each lens has a broadband coating that transmits more than 99 percent in visible wavelengths. The tube is aluminum and the dew shield slides

Astronomy TECHNOLOGY TODAY

31

THE STELLARVUE SV70T

Image 2 - The SV70T has a triplet objective with a center element made of Ohara FPL-53 glass, making it a true apochromatic telescope.

Image 4 - The focuser drawtube is graduated to allow users to record positions to return to for different eyepieces or cameras.

Image 6 - The focuser drawtube is graduated to allow users to record positions to return to for different eyepieces or cameras.

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Astronomy TECHNOLOGY TODAY

Image 3 - This view shows the two-speed focuser, heavy-duty Stellarvue tube rings and dovetail shoe for a finderscope that can be placed on other side of the top of the telescope using two socket cap screws as shown.

Image 5 - The SV70T attached to an Explore Scientific Twilight II altazimuth mount.

Image 7 - Stellarvue riser blocks come with two different-length Allen screws to accommodate different types of dovetail plates.

THE STELLARVUE SV70T back and forth for storage in the case or dew protection when in use. The tubeâ&#x20AC;&#x2122;s inside is flat black and baffled to minimize stray light reaching the focal point.

The focuser (Image 3) provides a full 2.875 inches (73 mm) of travel. The focuser has an ultra-smooth (11:1 ratio) fine focus control (gold knob) to attain perfect focus every time. The focuser drawtube is graduated (Image 4) to allow users to record positions to return to for different eyepieces or cameras. Focusing was easy for both visual use and CCD imaging, and a locking screw kept it in place.

As I mentioned earlier, the telescopes does not come with a finderscope. It does come with a standard-size dovetail shoe that allows many types of finderscopes or red-dot finders to be attached. The dovetail shoe can be attached to the left or right sides of the optical tube (Image 3). Stellarvue also carries several different types of brackets to attach red-dot or optical finders to the tube rings. As you can further see in Image 3, the tube rings have three 1/4-20

tapped screw holes on the top sides of the rings (the same on the bottom sides).

Due to the large dovetail bracket on the head of my Orion Atlas mount, the SV70T balanced fine in declination with the two-inch diagonal, large finderscope and large two-inch eyepiece. The same was not true when I attached it to my Twilight II Alt-Azimuth mount. The only way I could balance it was to use a lighter 1.25inch diagonal, with a smaller weight eyepiece, and forgo the finderscope (Image 5).

In this configuration, I could add a red dot finder to either tube ring and have no trouble vectoring target objects into view.

When I really want to travel light, this is how I will configure the telescope!

If I attach my Stellarvue 102T (Image 6 blue OTA) to the other side of the Twilight II mount, I can keep the heavier accessories on the SV70T. Balance is obtained by strategically positioning the larger telescope. I like having two side-byside telescopes to go back-and-forth viewing objects in a wide field and then a

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zoomed-in narrow field.

To get the SV-70T to balance on the Twilight II with the two-inch diagonal, 8x50 finder and large eyepiece, I used a longer dovetail plate and a set of the optional Stellarvue riser blocks (Image 7).

The riser blocks lift the tube rings 1.5 inches (38.1 mm) so that the dovetail plate does not hinder the focuser. The riser blocks come with two different length screws to accommodate different dovetail plate designs. This longer dovetail plate allows the assembly to balance, as seen in Image 8.

Image 9 shows how I can attach two refractors to the same German equatorial mount. This allows me to use the mounts go-to feature to find objects rather than star hopping with my manual alt-azimuth mount.

Stellarvue telescopes are made in California. They thoroughly test each one with star tests or on their optical bench. Interferometric test reports can be ordered at the time of purchase.

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THE STELLARVUE SV70T

Image 8 - A longer length dovetail plate is required to balance the telescope when using a 2-inch diagonal, eyepiece, and 8x50 finder.

Image 9 - The Stellarvue SV70T and Stellarvue SV102T, both on an Orion Atlas go-to mount.

Image 10 - The author mounted the SV70T in an observatory for CCD imaging with an SBIG STF-8300C CCD camera.

Image 11 - This image clearly shows Stellarvue 0.8x focal reducer/field flattener and required spacers between the telescope’s focuser and the CCD camera.

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Astronomy TECHNOLOGY TODAY

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THE STELLARVUE SV70T

Image 12 - NGC884 (left) and NGC869 (right), the Perseus Double Cluster taken with the SV70T with a 20-minute exposure.

I decided to visually test my scope before testing its CCD imaging capabilities.

Stellarvue states the visual performance of the SV70T is “simply stunning,” and it is.

With my 5-mm Nagler eyepiece (84x), I could easily spy the Cassini Gap in Saturn’s rings. Orion’s Trapezium was also clearly resolved. Star clusters were superb for a 70-mm telescope, and the colors were vivid. Lunar views were equally impressive.

Unlike larger telescopes, there was no need to stop down the aperture or use Moon filters.

With either a 26-mm Nagler or a 13mm Ethos eyepiece, I was able to capture all of the Andromeda galaxy and its two el-

liptical galactic companions. Orion’s entire sword filled the field of view, with M42 in its splendor. The telescoped captures an excellent wide-field view of the Pleiades with its scores of faint stars scattered around the Seven Sisters.

After visually testing the telescope, I brought it out to my observatory to test its imaging capabilities. I mounted it piggyback on top of an 8-inch Ritchey-Chrétien Cassegrain telescope (Image 10). Both rode atop a Software Bisque Paramount MyT German equatorial mount. For imaging, I used an SBIG STF-8300C singleshot color CCD camera.

For imaging, I used the before-men-

tioned Stellarvue 0.8x focal reducer/field flattener (FR/FF). The FR/FF has a 2.0inch barrel that slides right into the telescope’s focuser. Between the FR/FF and the camera are spacers (Image 11). Spacers are very important to optimize the benefit of the FR/FF to counter the field curvature inherent in short focal length refractor. If the spacing is not right, images will have elongated stars on the edges. I know, because I used the wrong spacing for the first images I took with this telescope. In addition to the 11-mm spacer installed on the Stellarvue FR/FF, an additional 55 mm of space is required between the CCD chip and the FR/FF. My CCD camera has 18 Astronomy TECHNOLOGY TODAY

35

THE STELLARVUE SV70T

Image 13 - The author captured this image of the Horsehead Nebula (IC434) and Flame Nebula (NGC2024) with a two-hour exposure.

mm of back focus, so I needed to attach 37 mm of additional spacers.

Fortunately, spacer kits are available with pieces 25, 10, 5, 2, and 1 mm that can be screwed together in any combination.

When using multiple spacers, I highly recommend placing the larger pieces on the camera and FR/FF and the smaller units in the middle. Those 1-mm and 2-mm spacers are hard to grip and unscrew from the camera to remove them.

Once I got the spacing right, the first picture I took was of the Double Cluster in Perseus (NGC869 and NGC884). The exposure was 20 minutes. Manually focusing the telescope with the camera was quite

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Astronomy TECHNOLOGY TODAY

easy and only took a couple of minutes.

Autoguiding was done with an SBIG ST2000XCM CCD camera on the RC8 reflector.

As can be seen in this uncropped image (Image 12), the stars are pinpoint and round from corner to corner. The color contrast between red and blue stars is superb. I have taken many pictures of the Double Cluster over the years with various telescopes, and this one is undoubtedly my favorite.

The next object I photographed with the SV70T was the Horsehead Nebula in Orion (IC434). I picked up sufficient data for the image with a one-hour exposure,

but I captured a second hour of data to bring out more faint detail in the red emission nebula surrounding the Horsehead.

Also in the image is the Flame Nebula (NGC2024). The brightest star in the image is Alnitak, one of three bright stars in Orionâ&#x20AC;&#x2122;s Belt. The color and detail obtained with only a 70-mm diameter telescope impressed me.

The quality and performance of the Stellarue SV70T is everything it is advertised to be. Over the years, I have come to expect nothing less from company owner Vic Maris. This is indeed an exceptional instrument that will stay in my equipment inventory for many years to come.

DESIGNING AND CONSTRUCTING A 28-INCH F/3.6 DOB Part 1 - Lessons Learned

By Tony Bryan

Editor’s Note: Part 1 of Tony Bryan’s twopart series on designing and building a big Dob starts with the macro – the lessons he learned from the trial-and-error process with which most of us approach such large projects. Part 2 will appear in the next issue of ATT and will cover the micro, the blow-byblow detail that was the fruit of those lessons.

First Things First So, you want to design and build your own large Dobsonian telescope? Perhaps money is no concern, and you are going for a mega-telescope … but not so fast. Big scopes are just that. They are big, they are heavy, and it often takes more than one person to safely move and set them up. Will you always have an observing buddy with you to help, or will your scope be permanently located? If not, perhaps you should scale back.

The 28-inch f/3.6 Dobsonian that I designed and constructed can be moved by one stout person on level ground or a very slight grade, but despite the mechanical advantage of extra-long, ergonomically stepped-in wheelbarrow handles, it is difficult. I am a fairly-fit 185-pound male, and it takes a lot out of me to move the lower portion of the scope to an observing spot. One person on each handle is welcome.

You can forget about lifting a large

Image 1 – The nearly completed mirror cell, constructed using 80/20 T-Slot 6105-T5 aluminum alloy.

Dobsonian into a truck or trailer, unless you have several physically-fit assistants available. Ramps and people to assist are required, even if you are a power lifter and think you can do it by yourself. When moving a large Dobsonian, always have a spotter to make sure things are going as planned, to guide, and assist. Picture your beautiful telescope toppling off your

trailer ramps and crashing to the ground.

More than cosmetic damage is likely to be inflicted.

Gather Your Reference Material I highly recommend first reading through The Dobsonian Telescope, A Practical Manual for Building Large AperAstronomy TECHNOLOGY TODAY

39

DESIGNING AND CONSTRUCTING A 28-INCH F/3.6 DOB

Image 2 – Mirror cell with three temporary side pins, sling, and the surrogate mirror constructed of laminated polystyrene foam board and cardboard.

ture Telescopes, by Dave Kriege and Richard Berry. Besides that title, there are a few other good books available for you to reference. Look at the reviews on the web and purchase or borrow a couple of titles that other ATMs have deemed es-

Image 3 – Rocker box during glue-up and clamping.

sential. Whatever you do, make sure the information you obtain from the web is by reliable sources. Study the books before you begin. Understand the pros and cons, weigh the alternatives for each element of the design, understand the com-

plexity of each task, and decide upon what is best suited for your needs and preferences. After you come to your senses, you might determine that a smaller aperture or shorter focal length is more preferred.

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hubbleoptics.com 40

Astronomy TECHNOLOGY TODAY

DESIGNING AND CONSTRUCTING A 28-INCH F/3.6 DOB Thereâ&#x20AC;&#x2122;s More Than One Way to Skin a Cat By no means do I suggest cruelty to animals. I use the proverb only to suggest that, as your design is put to paper, you can perform a trade study with regards to material selection, make-versus-buy decisions, and labor-versus-material costs. For instance, one may choose to save money by purchasing a less expensive item that needs to be modified (adding labor), over a part that is form-and-fit for what you need.

Depending on your budget, time constraints, and how much you enjoy (or not) tinkering with something to make it fit, all factor into your decisions. Some folks get great satisfaction out of being creative and saving money. Some folks would rather just spend the money and get it done. Take heed that sometimes a modification may cost more than buying an off-the-shelf option that is ready for your use. Once again, count all your anticipated costs to help in your decision.

Design Aids The use of free or low-cost software applications will dramatically increase the probability for a successful design, and will reduce the number of headaches you will have along the way. I used two software applications. The first, PLate OPtimizer (PLOP), is a CAD program by David Lewis, and it is a great tool to aid in the design of the mirror cell. It is free and available for download. You may have to run it several times to understand how it is determining the output files and trust that it is not going to lead you down a wrong path. The second was Microsoft Visio. Although not free, it made laying out all the piece parts much simpler and virtually guaranteed that it would all fit together.

Notwithstanding, I found that the use of physical models (cardboard templates and polystyrene foam board cutouts) after laying things out in Visio was very useful for such things as ergonomics and to serve as a surrogate for

Image 4 â&#x20AC;&#x201C; Mirror box during construction, along with the author.

Astronomy TECHNOLOGY TODAY

41

DESIGNING AND CONSTRUCTING A 28-INCH F/3.6 DOB

Image 5 â&#x20AC;&#x201C; Rocker box with finish applied.

Image 6 â&#x20AC;&#x201C; The authorâ&#x20AC;&#x2122;s daughter Ana and her husband Gio, who helped with moving and holding large panels, glue-up, and applying finishes.

the mirror. The primary mirror for the 28-inch remained in the box until a bench test of the focal length.

Start with the End in Mind Plan the whole job before beginning, and work to your plan as you go along.

This not only encompasses the work plan (tasks and order of execution), but the design as well. This doesnâ&#x20AC;&#x2122;t necessarily mean that every fine detail needs to be finalized.

Inevitably, you will find something along the way that needs tweaking, but if the design is not mostly mature, you might wind up with a lot of scrap along the way.

Costs Add Up Perhaps you already have an idea of how much your primary and secondary will cost, and are comfortable with those expenses. Although the optics are likely a large percentage of your cash outlay, the other costs can add up very quickly. Besides the focuser, hardware for the mirror cell, and secondary mirror hardware, it takes a lot of wood, plastic, Teflon, nuts, bolts, screws, stain, and other finishing products.

To put things in perspective, construction of the 28-inch consumed $36US of quality wood glue and contact

Â&#x2021;Â&#x192;Â&#x2020;Â&#x2021;Â&#x201D; Â&#x201D;Â&#x2018; Í´ Â&#x2039;Â&#x2DC;Â&#x2021; Â&#x2022;Â? Â?Â&#x203A; Â&#x203A; Â?Â&#x2018;Â?Â&#x2039;Â&#x2013;Â&#x2018;Â&#x201D;Â&#x201D;Â&#x2039;Â&#x2039;Â?Â&#x2030;

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2014

Â&#x2122;Â&#x2122;Â&#x2122;ǤÂ?Â?Â&#x2039;Â&#x2030;Â&#x160;Â&#x2013;Â&#x2122;Â&#x192;Â&#x201D;Â&#x2021;ǤÂ&#x201E;Â&#x2039;Â&#x153; 42

Astronomy TECHNOLOGY TODAY

adhesive. Also, if you decide to use stainless steel hardware for corrosion resistance and appearance, those items will cost much more than zinc or cad plated.

If you or a friend can sew, several hundred dollars can be saved on the shroud, if you decide to have one (which I strongly recommend for numerous reasons, including protecting your primary from dropped objects). All items required to make the shroud for the 28-inch totaled less than $50.00.

When you are making your design trades, there are some things where cost should not be weighed heavily. Donâ&#x20AC;&#x2122;t

220013St Star Prrooducts cts

DESIGNING AND CONSTRUCTING A 28-INCH F/3.6 DOB

Image 7 – Scott Conner (left) and the author measuring to cut truss Image 8 – Hours from first light. Look closely to see blue cord poles to final length while at Okie-Tex 2015. helping to hold the truss poles from riding up prior to redesign of clamp blocks.

cheap out on the focuser. Get a quality 2inch dual-speed Crayford-type, and you will not be disappointed. There are many nice ones of proven performance out there for around $300.00.

I would also suggest that you do not cut corners or cheap-out on the design of the primary mirror cell, or strength of anything that maintains the optical path (mirror box, truss poles, secondary spider, et cetera). To do so may result in a design plagued with instabilities, vibrations, or

springy motion, all of which cause frustrations and take the pleasure out of your hobby.

Setting-up Shop Basic hand and power tools might be fine for building a 10-inch Dobsonian telescope, but for a large one, a suite of stationary power tools may make the difference between a successful project and pile of scrap. Stationary power tools not only can handle larger stock, they can im-

prove accuracy of whatever operation you perform with them. A circular saw, jig saw, drill, router, miter saw, and orbital sander are needed, regardless. Other items, such as jigs, work-stands, fences, numerous clamps, and custom made fixtures, will be almost mandatory. Unless you have experience using all such tools, a large Dob project from scratch (not a kit) will be a very difficult task.

Always work with safety in mind.

Use safe work practices, wear proper

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43

DESIGNING AND CONSTRUCTING A 28-INCH F/3.6 DOB

Image 9 – Redesigned truss clamp blocks, alt bearing, lower section of shroud, and alt encoder.

clothing, and make sure to wear safety glasses when working with power tools.

Tenacity and time may be able to replace experience, but it cannot replace fingers or eyes.

Measure Twice, Cut Once You’ve heard the saying and know it means you should make absolutely sure that you’re making each cut in the correct place, but most of us forget this advice well before the end of any such long project. Two-by-four lumber is cheap – a mistake costs but a few dollars.

Not so the material you will be sawing while building your big Dob. Measure three times, if that’s what it takes to avoid scrapping a $60 sheet of veneer plywood or a $50 length of aluminum truss pole.

When you do make a cut, do so with accuracy. Sloppy cuts will cause you much difficulty during assembly. I recommend expanding the “doing something more than once” theme to include any calculations you make. Redoing the math a couple of times for each equation used is well worth the time spent so that you get it right. Speaking of math, you won’t be able to avoid it unless you buy a kit telescope. The Kriege-Berry text mentioned previously, contains the math you will need to be successful.

44

Astronomy TECHNOLOGY TODAY

Image 10 – TRedesigned transition ring assembly.

Don’t Underestimate the Time Unless you can time travel or have built a large scope before, don’t underestimate how many hours you will spend on a project of this magnitude. Jot down the number of hours you think it will take, and then multiply that by five. If you are a perfectionist like me, you’d better multiply by seven. I estimate that well over 1500 hours went into the 28-inch scope.

Remember that as part of executing the project, you will also be traveling to brickand-mortar stores (some of which may not be local to you), researching and shopping on-line, cleaning up after yourself, setting up and tearing down tooling, planning, and documenting your work. It adds up quickly.

If you have other people in your life, I strongly suggest that you get their buy-in before starting. You will likely need some moral support and encouragement along the way, and people close to you are a good source for that. My wife Donna was mine.

Except for when I was commuting or at my job, nearly every waking minute of the last month or so before the 28-inch saw first light was devoted to the build.

Solicit Help You’ve got some friends and family, right? Don’t be shy to ask for help. I am

fortunate to have Scott Conner as a close friend. Scott is a member, and currently is the vice president, of our local astronomy group. A man of selfless dedication, he served as president of that organization for 17 years. Besides being an expert amateur astronomer and allround nice guy, he is a talented welder, machinist, and machine tool programmer. Many elements of the design were a collaborative effort with Scott, especially when it came to anything metallic. The 28-inch Dob would not have been possible without his expertise and assistance.

If you are lucky enough to have friends who have skills in machining, welding, woodworking, or mechanical design, that’s great. Even if your friends don’t have those specialized skills, that does not preclude them from participating. Sheets of plywood are heavy and, even if you can lift things by yourself, maneuvering things for cutting and glue-up can be difficult or impossible if you don’t have an extra set of hands.

Don’t forget to thank your friends in some way for helping.

You may have to plan certain aspects of the build around the schedule of your helpers. If your helpers are a noshow, don’t get mad, just reschedule and (continued on page 47)

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DESIGNING AND CONSTRUCTING A 28-INCH F/3.6 DOB (continued from page 44) move to another task. I found it prudent to remain flexible and be grateful whenever help arrived.

Even your kids might be able to help with tasks such as sanding, de-burring, cleaning up the workspace, and fetching tools. Make it a family fun-time and celebrate finishing each task, or group of tasks, with ice cream, a movie, or some other treat. Make the treat a family function as well. Whatever you do, please insure that things stay safe.

Don’t ruin the joy of building your scope by having to make a trip to the hospital for yourself, or anyone else involved.

At First Light, You Learn You Are Not Finished You’ve completed your scope, so you think, but with each early use, you will find there is at least one thing that needs improvement. Some things you can live

Image 11 – Upper cage assembly and spider.

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Astronomy TECHNOLOGY TODAY

47

DESIGNING AND CONSTRUCTING A 28-INCH F/3.6 DOB

Image 12 â&#x20AC;&#x201C; Ergonomic two-piece wheelbarrow handles.

with, but others will necessitate a design revision. Big scopes can either be overly sensitive or unresponsive to operator inputs. You are dealing with a lot of mass, and it may take a few iterations to get things right.

First light for the 28-inch was at Okie-Tex 2015. It was there that the truss poles were trimmed to their optimal length to allow focus of all eyepieces that were planned for use. Although not recommended, there is nothing like traveling a thousand miles and doing final assembly in the field. In my case, it was a thrill to see things fall into place, but I was very confident that the design

48

Astronomy TECHNOLOGY TODAY

Image 13 â&#x20AC;&#x201C; Finished scope with shroud, power system, encoders, and Argo-Navis. At zenith, the eyepiece is 8 feet 2 inches (249 cm) from ground level.

was going to work. It would be sad to see someone in the field with opposite results.

During first light, it became obvious that the design of the clamp block that attached the truss poles to the mirror box needed improvement. After using the scope for a while, the poles worked their way up, but remained in the clamp block. A second design improvement was decided on after a couple of uses, and that was to add a transition ringassembly between the truss poles and the upper cage. Trimming the trusspole length was necessary to accommodate the thickness of the ring. The

upside is that it no longer takes two people to assemble and disassemble the scope. There is additional information on these revisions in Part Two of this article.

During Okie-Tex 2015, many people came over to have a view through the scope. The seeing there was magnificent, and everyone I met was friendly. A few folks spent several hours, and tried out their bino-viewers, and one plopped in the latest Howie Glatter laser (Howie himself ). Although it was evident that a few design tweaks were to come, I am happy to say that everyone reported excellent views.

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WHAT ARE SOLAR ECLIPSE GLASSES MADE OF? And why we don’t use a polarization filter.

By Eric Gentry

Image 1 - H-a image captured by Austin Grant during the June 5, 2012 transit of Venus.

Editor’s Note: Eric Gentry’s contribution to this issue first appeared on Quora.com on March 22, 2015, in response to the question, “What are solar eclipse glasses made of?”

Solar eclipse glasses typically need to meet two constraints: You need something which will block most of the light, and you need something that can provide structural

support, so it won’t fall apart while you’re staring at the sun. Thanks to modern chemistry, most of the ‘solar eclipse glasses’ you find, such as those offered by Amazon, https://www.amazon.com/Eclipse-GlassesCertified-Viewer-filters/dp/B00712I3JA, use a specialized plastic polymer – it’s cheap, durable and relatively easy to make.

An alternative approach is to make glass lenses, which also have some darkening material mixed in with the glass. Similar idea, but typically more expensive, just as glass sunglasses are usually more expensive than plastic sunglasses for related reasons.

Other approaches have included adding a darkening material as a surface Astronomy TECHNOLOGY TODAY

51

WHAT ARE SOLAR ECLIPSE GLASSES MADE OF? coating, such as Mylar. Perkins Observatory (http://perkins.owu.edu/solar_viewing_safety.htm) considers Mylar, which is essentially an aluminum foil laminated to thin plastic sheets, as unsuitable. Similar materials have been used as solar telescope filters, but because surface coatings are just that – only on the surface – they are also typically more fragile. You must worry about small scratches, or pinholes. If most of your eye is safe, but one part is getting fried ... then one part is still getting fried.

Which brings us to the next consideration.

What are solar eclipse glasses doing?

You’re not supposed to look directly at the sun because it’s bright and can cause damage to your eyes. It’s so bright, that seeing just 0.0032% of its light is at the upper limit of the “safe, but maybe uncomfortable range” (http://www.skyandtelescope.com/ observing/solar-filter-safety/

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Astronomy TECHNOLOGY TODAY

). So, you need to block a lot of the light … and you need to do it in all wavelengths which can cause damage to your eyes.

So, what about polarization filtering lenses? A single polarizing lens can block about 50 percent of the incoming light (well, slightly more, since the sun’s light is partially polarized after passing through Earth’s atmosphere). But for every polarization filter you add, you only ever can block out another 50 percent of the light (due to the strangeness of quantum mechanics). A single filter gets you down to 50 percent, adding a second filter gets you to 25 percent, and so on. At that rate, you’d need about 15 perfectly polarizing filters in a row.

Solar eclipse glasses and simple solar telescope filters deliver a mix of all visible wavelengths of solar light, or “white light.”

Much more interesting is the chance to see narrow bands of color. Most of the interesting effects happen at narrower wavelength bands, e.g the H-alpha wavelength, as shown in Image 1.

But this talk about different wavelengths is a reminder that, just because a material is blocking at one wavelength, doesn’t mean it’s blocking every wavelength. And there is a wide range of wavelengths that can damage our eyes.

We see visible light, but UV + IR (ultraviolet + infrared) light can also damage your eyes, even if you can’t see in those ranges. That’s why you need special materials for blocking sunlight -- you can’t just hold something in front of the Sun and think you'll be okay as long as it looks dark. For instance, exposed color film might block enough visible light, but it won’t block enough IR light to be safe. For other materials, maybe it's too much UV light. And these types of light can be nasty -- your blink reflex only responds to visible light, so if you only block the visible light, you’ll have removed your body’s natural protection while still leaving the damaging rays.

So, only use solar glasses and telescope filters marked specifically for use as such.

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August 21, 2017 AstroSolar™ SAFETY FILM PRESERVES OPTICAL QUALITY Astro-Physics is synonymous with optical quality so you know we are very particular about the solar filters that we recommend. AstroSolar Safety film from Baader Planetarium produces the highest contrast and sharpness in your visual or photographic image. As you observe the partial phases before and after totality, you will see sunspots and surface granulation in fine detail. The solar image is a very pleasing natural white without false blue or orange color.

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AstroSolar™ is available in sheet form in two sizes: 200 x 290mm (7.9” x 11.4”) or 500 x 1000mm (19.7” x 39.4”) so that you can make your own filters very inexpensively. It is also available in premade filters for your telescope or binocular. Stop by our website for additional information.

IMAGE INFO: Partial phases were photographed with Astro Solar™.

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Tele Vue and Al Nagler Celebrating 40 Years of Innovation

By Gary Parkerson

One of the highlights of my tenure as editor of ATT was the opportunity to meet Al Nagler. In an industry that boasts more than its share of larger-than-life innovators, I can think of none who’ve had greater influence. Introducing our new astro-tech publication at NEAF, the world’s largest astro-tech expo, could easily have been a nerve-racking experience, but Al was so gracious in taking the time to visit with me – so welcoming – all anxiety melted away. Instead, there I was, a rookie editor of an unproven, startup magazine, engaged in a long, friendly, illuminating chat with Al Nagler. For newbie editors, it didn’t get much better than that! Still doesn’t.

It wasn’t until years later – long after my initial fan-boy giddiness had calmed – that I realized what resonated most clearly upon meeting Al for the first time: generosity, kindness and honesty. In other words, he is not only a legendary astro-tech innovator, he iss a gentleman. When, several issues into our first year, Al told us how much he enjoyed the magazine, that was as close to the Good Housekeeping seal of approval as we could get.

I suppose Al’s innovative approach to product design represented the natural progression of his professional experiences from 1957 to 1973, working as a senior opticalsystems designer for the Farrand Optical Company, which developed visual simulators for several NASA programs. Included in Al’s responsibilities were the one-off displays for the Gemini and Apollo Lunar

Image 1 - Al Nagler with ATT representatives Chad Patterson, Austin Grant and Stan Westmoreland at NEAIC 2014.

Module spacecraft. The visual simulators used large mirrors to project images of Earth orbit, docking and lunar landing. The lunar landing was simulated by a complex optical probe, a TV camera and lens that “flew” down onto a scale model of the lunar surface.

Al’s unique experiences in developing these and other space-exploration technologies provided the technical foundation for all that followed, including the Renaissance Telescope, his patented wide-angle eyepieces and other optical systems that have been introduced by Tele Vue since Al created the

company in 1977.

To evidence just how thoroughly Tele Vue’s innovations are respected, its products have been represented in an amazing 16 of 19 Hot Products lists, since Sky &Telescope introduced that must-read annual feature in 1998. As the following list reveals, not only have Tele Vue products been honored in 16 S&T Hot Products lists, in some years the list included multiple Tele Vue products.

January 2015: BIG Paracorr.

January 2014: NP127fli Astrograph.

January 2013: Delos Eyepiece Line.

January 2012: Delos 6mm and Delos Astronomy TECHNOLOGY TODAY

55

TELE VUE AND AL NAGLER 10-mm.

January 2011: Ethos-SX 3.7-mm and Paracorr Type-2.

January 2010: Ethos 10- and 21-mm.

January 2009: Ethos Eyepiece Line.

January 2008: Ethos 13-mm 100°.

January 2007: “IS” Apo astrograph refractors and Paracorr for SBIG STL-series.

January 2006: DIOPTRX astigmatism correctors.

January 2004: TV-60 Apo refractor, 2- to 4-mm Nagler Zoom and 41-mm Panoptic eyepieces.

January 2003: 24mm Panoptic eyepiece.

December 2001: 3- to 6-mm Nagler Zoom and NP101 Apo refractor.

December 2000: 102 Apo refractor.

December 1999: 31-mm Nagler Type 5 and Radian-series eyepieces.

December 1998: 5x Powermate.

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Astronomy TECHNOLOGY TODAY

This year celebrates 40 years of Al’s pioneering optical designs with Tele Vue. Those years have inspired numerous articles that have chronicled Al’s life and innovations, and the revolutionary nature of Tele Vue’s product lines. It’s a cornucopia of insight that the Internet is kind enough to share. So, instead of my retelling a story that has been told so well through so many different voices, we will simply direct you to some of what we consider the best (or most interesting!) that are publicly available.

Tele Vue: A Historical Perspective Company7’s Mark Cohen published an extensive article covering much of Tele Vue’s history on the Company 7 website. It provides a comprehensive narrative of the early days of Tele Vue, including images of original early drawings of the “Nagler” eyepiece

design. You’ll find the article here: www.company7.com/televue/telal.html .

Al Nagler: The Amateur Astronomer Who Changed the Way We See the Universe Mike Smith with Australia’s Bintel (The Binocular and Telescope Shop) published this biography in the company’s monthly magazine. It provides nice insight into Al’s early experiences and how that period shaped his future astronomy endeavors. You can read the article here: http://www.televue.com/pdf/TV_Handout_NightSkyBioOnAlNagler.pdfs.

The Life and Times of Al Nagler Michael Bakich, Astronomy Magazine’s Senior Editor, wrote an extensive biography featuring Al Nagler in the April 2013 issue

TELE VUE AND AL NAGLER of Astronomy Magazine. The article shares compelling insight into Al’s life and his journey to becoming such a legendary figure in our industry. We particularly enjoyed the extensive photos, which help chronicle and illustrate the life stories of Al and his wife Judi. You can view the article at: http://www.televue.com/Pdf/Astronomy_LifeOfAlNagler_2013APR.pdf .

The Evolution of Eyepiece Developments at Tele Vue In 2015, Al contributed a guest blog post on Astronomy Magazine’s website, which provides a chronical of the process of the creation of Tele Vue’s many eyepiece innovations – from the original Nagler design to the conception of the latest Delite series.

You can read the article here: http://cs.astronomy.com/asy/b/astronomy/archive/20 15/10/13/the-evolution-of-eyepiece-developments-at-tele-vue.aspx A GuideStar Interview with Al Nagler In 2009, Clayton L. Jeter did a wideranging Q&A with Al for the Houston Astronomical Society’s GuideStar newsletter.

It’s an especially engaging interview, given its enthusiast’s point of view. You can read the article here: https://www.astronomyhouston.org/sites/default/files/guidestar/20 09_05_GuideStar.pdf .

My Day with Al Nagler On the Cloudy Nights forum, “Ron Bee” wrote a rambling post about a day in 2005, when he got to meet Al at Tele Vue’s display during OPT’s annual telescope show. After stopping by to say hi, Al invited him to spend the day at the booth. It offers a unique glimpse into the graciousness Al extends to all who share his enthusiasm for amateur astronomy. You can read the post here: http://www.cloudynights.com/ page/articles/cat/articles/special-events/myday-with-al-nagler-r1149 .

An Eyepiece Primer In 2006, Al shared the philosophies with which he approaches eyepiece design

in Sky & Telescope. It’s a must read for anyone who wants insight into his approach to creating eyepieces. You can read the article here: http://www.skyandtelescope. com/astronomy-equipment/an-eyepieceprimer/ Nagler Mythos…

In 2004, Cloudy Nights editor Tom Trusock took a deep dive into the entire Nagler eyepiece line. One especially interesting aspect of the article is Tom;s “Nagler Myths Dispelled” section. You can read the article at: www.cloudynights.com/documents/naglers.pdf .

Uncle Rod and Uncle Al “Uncle” Rod Mollise shared his experiences with Al (as only he can do!). One of the highlights of this article is Rod’s summary of the eyepiece choices he experienced from the beginning of his observing days in 1965 to Al’s introduction of his now-legendary eyepieces. You can read the article here: http://uncle-

rods.blogspot.com/ 2012/10/uncle-rodand-uncle-al.html .

NEAF 2014 Video Interview Sky & Telescope senior editor Dennis di Cicco conducted a video interview with Al, which provides an overview of the company’s history and how some of its ground-breaking eyepieces and telescopes came to be. You can view the video here: www.televue.com/engine/TV3b_page.asp ?id=13&Tab=_NEAF2014 .

Product Release Timeline We’ve included an insert here that provides a timeline of the product releases

by Tele Vue over the last 40 years.

The depth and breadth of transformative innovation included there is … well, it’s unprecedented. Congratulations to the entire Tele Vue team on an amazing ride! We look forward to enjoying the equally revolutionary innovations Tele Vue will, undoubtedly, introduce in the future!

by Jim Meadows

BOOKS TO HELP YOU GET STARTED As I got back into Astronomy, I developed books containing practical answers to the issues I encountered. The format of these books are simple and straight forward containing a list of questions with a discussion and pictures of the issue at hand.

Beginning Astronomy with a Celestron ... So, what's the matter?

Beginning Astronomy with a Celestron Equatorial Mount ...

So, what's the matter?

Beginning Remote Video Astronomy ... So, what's the matter?

These books are available in Kindle or Paperback format from Amazon. For more information, see http://www.amazon.com/author/jimmeadows

Astronomy TECHNOLOGY TODAY

57

TELE VUE AND AL NAGLER

A CHRONOLOGICAL HISTORY OF TELE VUE’S INNOVATIONS 1977 - Television Projection Lens 343-mm, f/2.6.

1978 - Television Projection Lens 279-mm, f/1.8.

1979 - Al Nagler begins design on telescopes and eyepieces for fellow amateur astronomers.

1980 - 55-, 26-, 17-, 10.4- and 7.4-mm Plössls ; 13-, 9- and 4.8-mm Naglers; 1.25-inch 2.5x Barlow.

1981 - MPT: 5-inch, 500-mm, f/4; 40-, 21- and 13-mm Plössls; 2-inch solid-aluminum machined mirror diagonal.

1982 - 2-mm Plössl; 40-, 32-, 24- and 19-mm Wide Fields.

1984 - 550-mm, f/5.5 Renaissance ; 15-mm Wide Field; 7and 11-mm Naglers.

1985 - 1.25-inch 1.8x Barlow.

1986 - 20-, 16- and 12-mm Nagler Type 2.

2002 - TV-102i for Bino-Vue; 26-mm Nagler Type 5; 24-mm Panoptic;2.0-inch 2x Powermate; 60-degree Everbrite diagonal.

2003 - 660-mm f/5.2 NP-127; 360-mm f/6.0 TV-60; 20-mm Nagler Type 5; 11-, 3.5- and 2.5-mm Nagler Type 6; 41-mm Panoptic; 2- to 4-mm Nagler Zoom; Mars Filters; BirdScope.com established; Focus Lever; Bandmate OIII Filter; Bandmate NebuStar Filter.

2004 - X-Y Adjustable Mount; Quick Release Universal Finder Mount.

2005 - 360-mm, f/6 TV60is imaging system; DIOPTRX Astigmatism Correctors; Click-Stop 8- to 24-mm Zoom for DIOPTRX; Focusmate Eyeguard extender.

1987 - 560-mm, f/7.4 Oracle.

1988 - 500-mm f/5.0 Genesis.

1989 - 2-inch 2x Big Barlow; Paracorr.

1991 - Solaris Solar Telescope; 450-mm, f/6.4 Pronto; Starbeam Unit-Power Finder.

1992 - 480-mm, f/6.8 Pronto; 22- and 35-mm Panoptics.

1993 - 540mm, f/5.4 Genesis-sdf, Renaissance-sdf.

1994 - 15- and 27-mm Panoptics.

2006 - 540-mm, f/5.4 NP-101is and 660-mm f/5.2 NP-127is “Imaging System” Telescopes; 880-mm, f/8.6 TV102iis; DIOPTRX Adapter for 24/19 Pan, N20T5 and NT6; Paracorr for SBIG; Focusmate Driver; Imaging System Components (Extension tubes, correctors, reducers, indicators); 2007 - 13-mm Ethos 100° eyepiece; Universal Paracorr for imaging with Newtonians; Focusmaster Auto-focus electronics for Focusmate driver.

1995 - 480-mm, f/6.8 Ranger, 25-, 20-, 15-, 11- and 8-mm; 1.25-inch 2x and 3x Barlows; Bino Vue.

2008 - 6-, 8- and 17-mm 100°-Ethos.

1996 - 540-mm, f/5.4 TV-101, Renaissance-101; 700-mm, f/5.0 TV-140; 19-mm Panoptic.

2009 - 10- and 21-mm 100° Ethos; 1.5x Extender for NP101is/NP127is Imaging Systems.

1998 - 600-mm, f/7 TV-85; 600-mm, f/7 Bizarro-85; 2.5x and 5x 1.25-inch Powermates; 22-, 17- and 12-mm Nagler Type 4; 18-, 14-, 12-, 10-, 8-, 6-, 5-, 4- and 3-mm Radians; 2x Bino Vue Amplifier/Corrector.

2010 - 3.7-mm SX 110° Ethos; Paracorr Type-2.

1999 - 2.0-inch 4x Powermate; 31-mm Nagler Type 5; 0.8x Reducer; 99-percent reflectivity Everbrite diagonal.

2000 - 880-mm f/8.6 TV-102, Renaissance-102; Visual Paracorr.

2001 - 540-mm f/5.4 NP-101; 480-mm f/6.3 TV-76; 16-mm Nagler Type 5; 13-, 9-, 7- and 5-mm Nagler Type 6; 3-6 Zoom Nagler; Sol-Searcher (Sun Finder); Universal Finder Mount; 90-degree flip-mirror Starbeam.

58

Astronomy TECHNOLOGY TODAY

2011 - 6- and 10-mm 72° Delos; 4.7-mm SX 110°Ethos.

2012 - 17.3-, 14-, 12-, 8-, 4.5- and 3.5-mm 72°Delos.

2013 - Planetary Filter.

2014 - 680-mm, f/5.3NP-127fli Astrograph; BIG Paracorr.

2015 - 18.2-, 11- and 7-mm DeLite; Gibraltar HD4 and HD5 Mount; FoneMate adapter.

2016 – 15-, 9- and 5-mm DeLite.

DIY

By Charles Jagow

Letâ&#x20AC;&#x2122;s start with some words of caution. This article is intended to serve only as a general guide to building custum dew heaters for your astronomical gear. When properly constructed, the resulting heaters are compatible with most commercial dew controllers, however, a mistake in construction could damage a controller.

Your use of these general instructions is entirely at your own risk. The dew heaters described here are only for use with a 12volt DC battery or 13.8-volt DC power supply. Higher voltages will overheat and damage them. Never power a dew heater with 120-volt AC due to the risk of electrocution. But you already knew all that.

I have personally made about two dozen of these strips for myself and others. I constructed my first set in 2004, and those are still in regular operation. So, I feel confident that I can help you have the same success. In 2004, I was faced with coming up with a dew-prevention system for my newly acquired Meade LX200GPS 10-inch SCT telescope and its 9x50 finder scope. I also wanted to have a dew-heater strip I could use for both 1.25-inch and 2.0-inch eyepieces. For the sake of this article, we will assume the same typical setup.

At a minimum, you are looking at one heating strip for the telescope objective lens, one heating strip for the finderscope objective lens, one heating strip for the finder-scope eyepiece and one heating strip for the telescope eyepieces.

A quick check on prices for average priced commercial heating strips yields

DEW HEATERS

Image 1 - A combined finder-scope dew heater.

the following prospective costs: one heating strip for 10-inch telescope, $50.50US; one 2.0-inch eyepiece heating strip for the finder-scope objective, $25.25; one 0.965-inch heating strip for the finder scope eyepiece, $23.00; and one 2.0-inch eyepiece heating strip for the telescope eyepieces, $25.25; for a total $124.00.

Not bad, for all that, but you can build a DIY equivalent for much less. You can make reliable homemade dew heaters, if you have a little bit of dexterity and are not afraid of a little soldering. If youâ&#x20AC;&#x2122;ve ever had fun doing arts and crafts, then this DIY solution is for you.

The basic concept is to assemble an electronic device resembling a ladder using 330-ohm 1/2-Watt (5-percent tolerance) resistors attached to a cable with an RCA-style plug on the other end. The resistive ladder assembly is backed with a

weather stripping on one side and a strip of electrical tape on the other side, and the entire resistive ladder is then sheathed in 1.0-inch wide heat-shrinkable tubing.

It will take some time to make your first heater strip, however, your follow-on units will take much less. I needed to make a heater strip for my Canon 28-135 mm lens, and it took me an hour and fifteen to make the dew heater, including setup/cleanup and taking most of the pictures used in this presentation, and I saved just over half the cost of a commercial dew heater strip.

Parts and Tools Required Here is a list of the parts you will need to make homemade dew heaters for the above equipment: â&#x20AC;˘ Telescope Objective, 37-inch circumference, 62 resistors; Astronomy TECHNOLOGY TODAY

61

DIY DEW HEATERS This is less than half of a low-priced commercial solution! It’s even less, if you already have some of the items, and you can make more heater strips for just the cost of the extra resistors, RCA cables and heat shrink.

Image 2 - Straightened 330-ohm resistor.

Image 3 - Lead bent at 90 degrees roughly 1/4 inch from the resistor body.

• Fider Scope Objective, 7.5-inch circumference, 14 resistors; • Finder Scope Eyepiece, 4.5-inch circumference, 10 resistors; • Eyepiece, 9-inch circumference (largest one), 17 resistors; • Three 6-foot Radio Shack cables, RCA plug to tinned leads, P/N 42-2371A; • Two lengths of 1-inch by 48-inch heatshrinkable tubing; • One roll of electrical tape;

62

Astronomy TECHNOLOGY TODAY

• Approximately 130 inches of weather stripping, 3/8 inch by 1/8 inch; and • About 6 feet of string for measuring.

I priced most of the items as follows: 330 ohm resistors, 130 @ $0.22 = $28.60; Radio Shack RCA 6-foot cables, three at $4.80 = $14.40; heat shrink, 1.0-inch wide x 48-inches, two at $3.88 = $7.76; weather stripping, 1/8 inch by 3/8 inch by 17 feet, $4.99; electrician’s tape $1.52; solder, $3.49; Total $60.76.

The tools you will need are: • Small (about 3.5-inch) round-nose or needle-nose pliers; • Multi-meter capable of measuring resistance, in Ohms; • 30-Watt pencil soldering iron with a fine/medium tip; • Solder; • Small diagonal cutters; • Scissors; • Ruler or small tape measure; • Heating device for heat shrink tubing (butane BBQ lighter, paintstripping/heat gun, etc.); • Small wet sponge, to clean the soldering iron tip; • A small piece of flat scrap wood to solder on (I use a piece 10 inches by 4 inches by 1.0 inch); and • A small work light (optional).

You can find the parts and tools required for this project through the following sources: • Resistors, 330 ohm, 1/2-Watt, fivepercent tolerance, $0.22 each (www.be-electronics.com/ product_p/ 1-fslash-2watt-330r.htm); • Radio Shack RCA tinned lead cables, P/N 42-2371A, $4.80 each, (www.ebay.com/ itm/RadioShackRCA-Male-Phone-to-TineedStripped-End-42-2371-/ 262116584658); • Heat Shrinkable Tubing, 1-inch by 48-inch, 2:1, $3.88 each, (www.beelectronics.com/product_p/ 1blu.htm ); • Electrical tape $1.52 per roll (www.beelectronics.com/product_p/ 1blu.htm) ; • Weather Stripping, White K-profile, 1/8-inch by 3/8-inch y x17-feet, $4.99 each (www.southerntoolky.com/

DIY DEW HEATERS

•

•

•

•

WEATHERSTRIP-EPDMADH17FT-WHT-p/5449251.htm ); Solder, $3.49 per roll (www.mpja.com/ Solder-Lead-FreeSn965_Ag30_Cu05/ productinfo/30090%20TL ); Multimeter with digit display, $14.95 each (www.mpja.com/3-1_2-DigitBacklit-Digital-Multimeter/product info/14213%20TE ); Long Nose Needle Nose Pliers, 3.5inch, $1.95 each (www.mpja.com/ LONG-NOSE-PLIERS/productinfo/ 17013%20TL ); and Soldering Kit, $7.95 per kit (www.mpja.com/30-Watt-SolderingIron-and-Accessories/product info/ 16431%20TL ).

Measuring The adage “measure twice, cut once” is good, but when I am doing things, it sometimes turns into measure twenty-seven times, cut three or four times, cuss and then go buy more materials and start over. It is good to know our measurements are not that critical – a tolerance of plus-or-minus a quarter inch is fine.

Find a length of string, and wrap it around the point on your telescope’s optical tube assembly (OTA) where the heating strip will lie. For my Meade, this is a spot about 2.25 inches from the edge of the OTA, just about where the blue tube starts. I measured a circumference of 37 inches, so that means the diameter of the tube is about 11.75 inches (37 inches divided by pi (3.141592654 as memorized since 3rd

grade). So, if you figured 31.15 inches – the telescope aperture of 10 inches * pi), you would end up with a heater strip woefully too short. That is why we are using the string.

Measure this circumference with the string for each of the devices you wish to wrap a heater around, and then round up to the next inch. I used 5.0 inches for the eyepiece on the finder scope, 8.0 inches for the finder scope objective and 9.0 inches for the eyepieces. I measured my Nagler 17-mm, as it is my widest eyepiece.

Resistors Construction of the resistive ladders requires one resistor for each 5/8 inch of length. So, we divide our length measurements by 0.625, and round up, and then add two more resistors for good measure (believe me, you will be glad you did later). This calculation yields a count of 62 resistors for the telescope-objective ladder, 10 for the finder-scope eyepiece, 14 for the finder-scope objective and 17 for the eyepiece heater strip.

Resistance, Current and Amperage Accounting for resistance, current and amperage is important and needs to Table 1 Heater-Strip Assembly Telescope Objective Eyepiece Finder-scope

Resistors 62 17 24

Image 4 - Both leads bent at 90 degrees.

be kept in mind when selecting or building a dew controller or power-distribution system for the heater strips. The requirements of this project are detailed in Table 1.

Calculated resistance of the 62 resistors for the telescope-objective heater strip is, for example, 5.32 ohms. With a fivepercent tolerance, the expected resistance range would be 5.06 to 5.6 ohms. This five-percent tolerance range is also applicable to the other listed assemblies. To make your calculations easier, I recommend using a web-based Ohm’s law calculator such as the one found at: http://www.sengpielaudio.com/ calcula-

Resistance 5.32 19.41 13.75

Amps 2.25 0.62 0.87

Watts 27.06 7.42 10.47

A big Dob on an Equatorial Platform is the ultimate observing machine. The Platform gives you precision tracking, whether you are observing with a high-power eyepiece, imaging with a CCD camera,or doing live video viewing with a MallinCam. Just check out this image of NGC3628 taken by Glenn Schaeffer with a 20-inch Dob on one of our Aluminum Platforms!

Visit our website for details about our wood and metal Equatorial Platforms, as well as our line of large-aperture alt/az SpicaEyes Telescopes. You can also call or email for a free color brochure.

274-9113 • tomosy@nccn.net EQUATORIAL PLATFORMS (530) www.equatorialplatforms.com Astronomy TECHNOLOGY TODAY

63

DIY DEW HEATERS

Image 5 - Resistor with hooks bent in ends of leads.

tor-ohm.htm.

A special note on construction of the heater strip for the finder scope is required. The two heaters for the finder scope should be connected in such a manner that the end of one resistive ladder is Table 2 Heater-Strip Assembly Resistors Finder Scope (objective) 10 Finder Scope (eyepiece) 14

connected to the other resistive ladder separated by a short ~10-inch pair of 18gauge wires, as shown in Image 1. The entire finder-scope heater assembly is powered from a single RCA cable.

The two ladders, a 10-resistor ladder and

Resistance 33 23.57

ASTRO ONOMY TECHNOLO OGY TODAY Your Complete Guide to Astronomical Equipment astronomytechnologytoday.com

Offer On ne

Amps 0.36 0.51

Watts 4.36 6.11

a 14-resistor ladder, are electrically the same as one 24-resister ladder this would create a total resistance of 13.75 ohms.

The requirements of the finder-scope objective and eyepiece strips are detailed in Table 2.

Construction The concept behind the resistor ladders is simple. Space the resistors so they are about 5/8 of an inch (15.9 mm) apart. This is not critical, but if adhered

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Astronomy TECHNOLOGY TODAY

DIY DEW HEATERS

Image 6 - Two resistors linked up forming two steps of the resistive ladder.

to, the previous calculations will be accurate. Once straightened out, each resistor will end up with a 90-degree bend in the lead at 1/8 to 3/16 of an inch (3.2 to 4.8 mm) from the body of the resistor – this is the most critical measurement. If you go wider, the whole she-bang won’t fit in a 1-inch wide heat shrink tube. When the leads on both sides of the resistor have been properly bent, the width should be about 3/4 of an inch (19 mm). Image 2 shows a

Image 7 - Five-step segments.

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DIY DEW HEATERS

Image 8 - A sixteen-resistor ladder made from three segments – two segments of five each and one of six.

Image 9 - Resistive ladder on the weather stripping material.

Image 10 - Resistive ladder sandwiched between electrical tape & weather strip material.

Image 11 - The heater strip enclosed in heat shrink, ready to apply heat.

straightened 330-ohm resistor, Image 3 shows the same resistor with a 90-bend located about 1/4 of an inch from the resistor body and Image 4 shows both leads bent at 90 degrees.

Next, bend a small hook in the ends of the leads, these will hook onto the next step of the resistive ladder. Bend several more resistor “steps” just like the first one before moving on.

Once you have several steps of the

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Astronomy TECHNOLOGY TODAY

ladder prepared, carefully attach one resistor to another such that the hooks fit into the 90-degree bends of another resistor, as shown in Image 6.

Connect five steps at a time as a segment, as shown in Image 7. Individual segments of five steps each are easier to work with than one long chain. Once you’ve assembled enough five-step segments, connect them together (Image 8).

Once your segments are all connected, it is time to solder. Give your soldering iron plenty of time to heat up.

It should be hot enough to melt the solder as it touches the tip of the iron.

Use a wet cloth to clean the tip of the soldering iron after every five or six solder connections. It will only require a small bit of solder on each connection.

As you solder sections together, try to keep them shaped in a straight ladder

DIY DEW HEATERS type of arrangement. Very slight deviations will not matter. You should also solder the leads of the tinned ends of the RCA cables to the ladder, one lead to each side of the ladder. Polarity does not matter with this resistive circuit.

Just make sure that when you are done, the leads soldered to the RCA cable do not touch together and cause a short circuit between the sides of the ladder.

Cut a length of weather-strip material that is long enough to extend past the end of the resistive ladder about one inch. It should also extend the other way an inch or so past the RCA cable connection. Peel off the adhesive cover and place the weather strip with the sticky side up. Now gently place your resistive ladder and cable centered on the weather strip, as shown in Image 9.

At this point, it might be wise to conduct some checks on your work before we continue. Referring to the table of resistance, amps and wattage, measure the resistance between the center pole and outside conductor of the RCA plug.

You should measure a resistance value as listed in the table within a +/- 5-percent tolerance window. If you have readings other than that there is a problem in the construction. It is very bad if a short (almost zero resistance, the same as if the leads to the multi-meter are shorted together) circuit exists as a fire could result.

If you have an “open” (infinite resistance), the heater strip will not work. If you have too much resistance, then one or more of the steps are somehow shorted together (I have never encountered this). Correct any such issues before continuing.

Now, carefully cut and apply a single piece of electrician’s tape along the full length of the weather stripping material covering the bare resistors. You should end up with the resistive ladder sandwiched between the electrician’s tape and the weather stripping, as shown

Image 12 - Heater strip after shrinking and shaping.

Image 13 - Finished heater strip for a DSLR.

Astronomy TECHNOLOGY TODAY

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DIY DEW HEATERS in Image 10.

Cut a small square of weather stripping material and place it between the leads of the resistive ladder that are soldered to the tinned leads of the RCA cable. This provides extra insulation so that the two leads do not short each other.

Cut a length of the heat-shrinkable tubing that extends an inch past the end of the ladder and covers out an inch or so past start of the insulated body of the RCA cable. The heat shrink should cover all exposed wire, leads and solder joints (Image 11).

Now comes the fun part: The heat shrink must be heated and shrunk over the resistive ladder assembly. Care must be taken to not apply excessive heat. Too much heat may melt the internal weather stripping and/or electrical tape. I bought

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Astronomy TECHNOLOGY TODAY

an inexpensive paint-stripping gun from Sears that has a high and low setting. Experiment with your heat source and a small piece of heat shrink to gain an understanding of its characteristics before continuing.

Apply heat starting at one end and roll the heat source around the heater strip ensuring the heat shrink tubing shrinks evenly as possible all around, move from one end to the other.

At this point, you should start to shape the heater strip in an arc that will fit your application. Remember, the entire assembly is hot, so be careful!

I generally take an empty soda or vegetable can to wrap the ladder around.

The shaping is easier once you start applying heat. You can apply heat to help make the assembly more malleable.

Once you have completed the

shrinking and shaping step, go back and check the resistance measurement again.

It should be the same. If not, it is troubleshooting time. You can carefully cut the shrunk heat shrink with a small pair of sewing scissors being careful not to cut any of your electrical connections.

The most likely culprit will be a damaged solder connection, a short or an open.

Attaching the heater strip to your device can be done in several ways. I use a small strip of double sided Velcro (hook-loop). On objects from which I do not plan on removing the heating strip, I use small cable ties. You can get very creative on ways to attach the heating strip. Donâ&#x20AC;&#x2122;t trim up the edge of the dew heater strip too closely, or the end resistor may become exposed and vulnerable.

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CELESTRON LITHIUM POWERTANK

The evolution of the lead-acid and lithium-ion battery finally adds convenience to the revolution of affordable go-to mounts.

By George Stallings

The leaps between the technology of today versus that when I received an unmotorized equatorial 114-mm Newtonian reflector as a 10-year-old in 1988, are mind boggling. I would have barely recognized today’s average reflectors, with red-dot finders, go-to drives, things that plug and unplug, and that use something called GPS to know where and when they are. However, until recently, what I (as well as my great-grandparents) would have recognized immediately is the nearly anachronistic power source of these technological marvels: lead-acid batteries. The irony is, old-technology batteries power many of today’s lightweight, advanced go-to mounts. These batteries often weigh nearly as much as the mounts to which they provide power.

For years, I have been using a very reliable, relatively powerful, 12-volt, 22-Ah Sears DieHard 1150 (Image 1) sealed lead-acid battery. As was the case with consumer batteries until recently, with great power comes great weight. My trusty old power source weighs in at a hefty 22 pounds (10 kilograms). In comparison, my grab-and-go setup, which consists of iEQ30 Pro mount with a 10-pound counterweight, lightweight tripod, and Celestron C8 optical tube assembly, weighs less than 50 pounds (22.7 kilograms) … without a battery. After carting this setup, plus its 22-pound battery, around to my local observing sites for a couple years, I decided

Image 1 - The 2.25-pound, 84.4 watt-hour PowerTank next to a 22-pound, 12-volt, 22-Ah Sears DieHard 1150 sealed lead-acid battery

I needed a less-weighty alternative that could put some more “go” into my almost “grab and go” telescope. Also, I was looking for a battery that could provide power to my heavier Sky-Watcher EQ6, as well, which is why I decided to buy Celestron’s new Lithium PowerTank.

What Is It? Celestron’s Lithium PowerTank is an 84.4-watt hour (7-amp hour at 12-volts), new class of rechargeable 12-volt battery that employs lithium iron phosphate (LiFePO4) as its cathode material. In comparison to lead-acid or other lithiumbased rechargeable battery chemistries,

lithium iron phosphate batteries provide increased charge/discharge cycles (up to 2,000 recharges) and faster recharge rates.

They are intrinsically safer than lead acid or other lithium-based battery chemistries, so they are less likely to catch fire with proper usage, cannot leak acid and are chemically stable and non-toxic.

They also have significantly improved energy densities over lead-acid batteries (Wh/kg), thus weighing much less per watt of power provided than lead-acid battery types. Unlike other lithium ion batteries, they have a nearly constant discharge voltage, an important characteristic for mounts that are sensitive to voltage

Astronomy TECHNOLOGY TODAY

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CELESTRON LITHIUM POWERTANK

Image 2 - The PowerTank attached to a tripod leg with the included Velcro strap.

input, such as my mounts are.

Another important aspect of LiFePO4 batteries is that they have a greater depth of discharge, without incurring damage, than lead acid batteries have.

Generally, while lead-acid rechargeable batteries can provide up to 50 percent of their rated capacity before causing permanent damage, LiFePO4 batteries can provide up to 90 percent of their rated capacity without incurring damage.

This means that, in theory, I can expect the 2.25-pound Celestron Lithium PowerTank to provide at least half the watt-hours of power as my 22-pound DieHard lead-acid under equal conditions and precautions.

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Astronomy TECHNOLOGY TODAY

What Is Included The body of Celestron Lithium PowerTank contains an adjustable-brightness red light, as well as a white-light â&#x20AC;&#x153;illumination panel,â&#x20AC;? along with two 5-volt USB charging ports with current outputs of 2.1 amps and 1.0 amp, and one charging/12-volt DC output port. The battery comes supplied with a Velcro strap to attach to tripod legs, as well as strap with clips to allow users to hang it from any place on the mount or other anchor point (Image 2). It also includes a dedicated charger that converts an input of 110- to 240-volt to the 16-volt DC at which the PowerTank is charged. This charger is supplied with input plug adapters that will work in mains electrical outlets worldwide, befit-

CELESTRON LITHIUM POWERTANK ting its portability. An included 2.1-mm x 5.5-mm DC plug supplies power to the mount.

How It Works The battery is intuitive to use. Pressing the power button (Image 3) once charges connected USB devices. Similarly, pressing the power button once provides power to the mount, when the mount is connected. The power button will also illuminate the power indicator lights, displaying the remaining charge left in the battery. Four illuminated lights mean the charge is full, while three, two, and one illuminated light(s) indicate a 75-percent, 50-percent, and 25-percent remaining charge respectively.

Pressing the lighting control button once turns on the LED red-light illumination panel, while pressing this button a second time increases that lightâ&#x20AC;&#x2122;s brightness.

Pressing the lighting control button a third time will turn the light off. Pressing the lighting control button for two seconds activates the white light. As with the red light, once the white light is turned on, pressing the light button a second time will increase the white lightâ&#x20AC;&#x2122;s brightness, and pressing it a third time will turn the white light off. It is possible to use the lights while the battery is providing power to the mount. However, in my unit, it was not possible to charge USB devices while providing power to the mount.

Performance Celestron advertises that the Lithium PowerTank provides up to ten hours of telescope runtime, a figure that is not overly optimistic with my equipment in both ideal conditions and in real world use. Indoor slewing and tracking testing revealed a runtime of a little more than 8.5 hours using a well-balanced Celestron C11 mounted on a Sky-Watcher EQ6. This runtime was not to the point of failure of the battery, but it was to the point at which the mount began to show some of its telltale signs of low-voltage operation (e.g. flashing power light).

While the runtime was not quite the advertised 10 hours, the Lithium Power-

Image 3 - PowerTank control panel.

Astronomy TECHNOLOGY TODAY

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CELESTRON LITHIUM POWERTANK

Image 4 - PowerTank with included accessories.

Tank’s runtime exceeded by a factor of nearly two that of a 6.0-Ah (72Wh) lithium cobalt oxide-based rechargeable battery I purchased previously. Possibly, this is due to

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Astronomy TECHNOLOGY TODAY

the steadier voltage output of LiFePO4 batteries. The battery’s performance is better than I expected for a mount with an estimated power consumption of up to 2.0

amps (24 watts) while slewing and up to 1.0 amp (12 watts) while tracking under load. As these power consumption figures for my iOptron iEQ30 Pro are 0.6A (7.2 watts) and 0.4A (4.8 watts) respectively, I expect the Lithium PowerTank’s performance to at least meet, and possibly exceed, Celestron’s advertised runtime when paired with that mount.

During several observing sessions at temperatures near or below freezing with the EQ6 and the Lithium PowerTank, I have never consumed more than 50 percent of the available power from full charge, as indicated by the charge indicator lights. These sessions averaged about 3.5 hours each. Battery charge time from near flat to full is less than four hours.

The form factor of this battery points to its design by an astronomy-equipment manufacturer specifically for amateur as-

CELESTRON LITHIUM POWERTANK tronomers. For example, the shape of the battery casing allows it to lie flat or hug rounded tripod legs. This ability to affix the battery to a tripod reduces its tendency to act as a trip hazard in the dark. Further evidence of design intent are covers for the power jacks and USB ports to keep dew from finding its way into the battery’s internal compartment. Similarly, the default LED illumination choice is the red, which makes it more difficult to activate the dark vision-ruining white light accidently – a nice touch.

The Revolution No Longer Weighs a Ton While not as revolutionary as the advent of affordable go-to mounts, the technology this battery employs makes go-to mounts much more convenient to use in terms of weight. My iOptron iEQ30 Pro and Celestron C8 combination is now much more portable and convenient. This tends to happen when a battery that weighs nearly half as much as the rest of the setup is no longer necessary. Another way to consider it is this: When I decide to take the Lithium PowerTank with me, as opposed to the DieHard 1150, I subtract a weight equal to that of a Celestron C9.25 from that evening’s observing gear.

In practical use, the PowerTank weighs so little that twice I have forgotten that I had already packed it as I headed out for observing sessions. While it does not turn my EQ6 paired with a Celestron C11 (Image 5) into a grab-and-go, ultraportable setup, it makes for two fewer trips to the car. With hands numb from the cold at 3:00 a.m., even one less trip does not go unappreciated.

The LiFePO4 is a dedicated power source for my mount. While it can also charge peripherals via USB ports, it is not a complete replacement of the large leadacid batteries for everyone or all situations.

But that is not the design intent of the product. While 84.4 watts of power is perfect for an evening’s visual observing sessions, enthusiasts who require heated dew

Image 5 - PowerTank powering an EQ6 carrying a C11.

control most nights, and who need power for laptops, CCD cameras, cooling fans and other accessories, will find they still need their large batteries. This is a battery for people who just want to observe or who want to power their mounts separately from other equipment. For these purposes, it is a perfect weight and capacity for graband-go and high-capacity mounts alike.

While I still need that 22-pound DieHard 1150 on occasion, most nights, I can now go out without it.

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ASTRONOMY

TECHNOLOGY TODAY Your Complete Guide to Astronomical Equipment

LOOKING BACK SERIES - Sept. - Oct. -

2015 2014 Pages 77-82

- Nov. - Dec. -

Pages 85-89

observing the sun in color with the mallincan xtreme - TURN ON THE SUN Cliff DE LACY

THE ASTRO HUTECH HINODE SOLAR GUIDER AUSTIN GRANT

Editorâ&#x20AC;&#x2122;s Note by Gary Parkerson:

As with other recent issues in anticipation of the August 21, 2017 solar eclipse, our continuing Looking Back series features solar-observing and imaging coverage that remains as topical today as when first published. Enjoy!

76 Astronomy TECHNOLOGY TODAY

Observing the Sun in Color with the MallinCam Xtreme Turn on the Sun!

By Cliff De Lacy

Editor’s Note The MallinCam video cameras have revolutionized the way amateur astronomers see the night sky. Apertures have been effectively quadrupled, cut through light pollution like a hot knife through butter and put color into otherwise faint targets.

But while we’re all familiar with what it can do for deep-sky objects, what isn’t as widely known is that you can turn the MallinCam towards the Sun and be met with the same jawdropping results. Cliff De Lacy shares his experience on how this great little video camera has changed his perception of our closest star.

Using the MallinCam Xtreme for colorful observations of the Sun This article focuses on the MalIinCam Xtreme, the color video camera handcrafted in North America by Pro Com Electronics. The Xtreme is one of a long line of color MallinCam cameras. In operation since 1985, this is the oldest and most experienced company in the industry to produce observational video cameras to project live images on monitors and television screens for professional and amateur astronomers.

You can just sit back in a chair while the live images appear on the screen, and while you can use this setup at stargazing events, you can also use it to observe the Sun during the day. It’s an amazing way to show the public the night sky or the Sun, and if you are into research – as I am – looking for asteroids, comets or observing the Sun, then this is the video camera for you.

I started observing the night sky in the 1940s. I built my first telescope from an article in the Mechanics Illustrated magazine in 1949. It was a 4.5-inch reflector Astronomy TECHNOLOGY TODAY

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OBSERVING THE SUN IN COLOR WITH THE MALLINCAM XTREME – PART 1

Image 3 - This is the output to either a TV or monitor.

Image 1 - The business end of the Mallincam Xtreme.

Image 2 - The input side of upscale unit.

Image 4 - The camera image sensor is protected from physical contact and shielded from light by a supplied cap.

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OBSERVING THE SUN IN COLOR WITH THE MALLINCAM XTREME – PART 1 using a cardboard linoleum tube and wooden saddle arrangement. My first night out, I was viewing the Moon at first quarter and remember seeing a black circular object about the size of a pinhead held at arm’s length at 100x. It had taken about 45 seconds to travel from the terminator to the horizon. About 10 years later, an astronomer told me I had seen an asteroid cross in front of the Moon. Wow! I could have named it if I had known who to call. Back then, I had no idea that someday we would be able to see deepspace objects in color.

A recent article on the MallinCam Video Camera in Astronomy magazine inspired me to contact company owner Rock Mallin to express an interest in testing the MallinCam with a Meade Coronado SolarMax 90 II with double-stacked Etalon filters. He referred me to Jack Huerkamp, owner of Jack’s Astro Accessories, MallinCam’s U.S. distributor, and Jack agreed to send me the MallinCam Xtreme on loan.

I research solar activity and wanted to be able to sit back in my observatory and watch the Sun in real time and take still pictures, as well, and that is what the Xtreme video camera provides: live-action video observational astronomy and astrophotos at the same time. I also planned to test the Xtreme in the field for solar gazing for students at schools, colleges, museums, public events, etc. As a Volunteer Solar System Ambassador appointed by the Jet Propulsion Laboratory since 2003, I help promote their outreach programs.

Setting up the Xtreme The back of the Xtreme has connections for cables and buttons for making adjustments for imaging (Image 1). The pixel size of the Xtreme is 8.4 µm by 9.8 µm with a chip dimension of 4.8 mm by 6.5 mm. The camera comes with a 110volt AC to a 12-volt DC power supply, a 25-foot power/video cable and a 1.25-inch adapter. The focal reducers and upscaler/video-capture device (Image 2 and

3) to change the image to HDMI 1080/ 720p are optional accessories. Motioncoding technology is supplied to make the picture rich in color and more vivid.

I downloaded the MallinCam Xtreme user’s manual from their website. It is well written, covers all aspects of setting up the camera and includes reports by individuals on the use of the Xtreme.

The manual specifically states – and this is critical in regards to solar observing – “Do not connect the camera to your telescope until the menu settings are completed. The camera needs to see a dark image while checking the color bar and other options for observing. The camera is sensitive to light and the image sensor must be covered at all times during camera setup.”

The next thing I did was to check the Xtreme to obtain a video signal. I made sure the camera was off and the cover in place over the image sensor, as shown in Image 4. I attached the cables to the upscale device and a 32-inch TV. With cables attached, I turned on the TV and held down the center menu button on the back of the Xtreme (Image 1) for about 2 seconds to reveal the Xtreme’s main menu (Image 5).

I then checked the color signal (color bar) coming from the composite port (S video) by depressing the top and bottom menu buttons simultaneously, then moved the arrow pointing to the option menu and again pressed the center button. The option menu was shown in Image 6.

Using the down button I selected the last entry – “Return” – and pressed the right arrow button. “Return” changed to “Next”. I then pressed the center button, and the display was showing the Option 2 screen (Image 7).

Using the back arrow button, the color bar option said “off,” and I activated it by pressing the right button. The menu then showed the color bar on the TV screen (Image 8) to be adjusted to sharpen the image.

Image 5 - This is the Xtreme’s main menu as it presents on the TV screen.

Image 6 - The Mallincam Xtreme option menu.

Image 7 - The Option 2 menu with color bar off.

Once the color bar was shown, I adjusted the colors as I felt necessary. I went back to the color bar option, which was “on” and deactivated the option by pressing the right button, which changed the color bar to “off. You can also turn the color bar off by repeating the steps to turn it on by depressing both the top and bottom buttons again.

I had not yet connected the Xtreme to my 90-mm SolarMax. You may discover that, although you are satisfied with

Astronomy TECHNOLOGY TODAY

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OBSERVING THE SUN IN COLOR WITH THE MALLINCAM XTREME – PART 1

Image 8 - The same Option 2 screen with color bar on.

the live image obtained against the color bar, you may want to readjust the colors to bring out more detail in the Sun. Focal Reducers I also ordered MallinCam’s optional MFR-5 focal reducer, a two-cell design

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Astronomy TECHNOLOGY TODAY

Image 9 - The MRF-5 focal reducer components explained.

that allows use of spacers between the cells to achieve further focal reduction and is made to mount the C-mount video camera to your telescope. The barrel on the larger reducer part listed in Image 9 as part “A” has internal threads for filters.

The MFR-5 is ideal for all telescope designs, including SCTs, RCs and CDKs. Both parts have male C-mount connecters for the attaching to the camera. Cell “B” has about a 0.8x focal reduction, while cell “A” provides about 0.75x focal reduction by itself. You can

OBSERVING THE SUN IN COLOR WITH THE MALLINCAM XTREME – PART 1

Image 10 - The optional wired exposure-control unit.

also use both parts of the MFR-5 to achieve about 0.4x focal reduction.

Operating the Xtreme The Xtreme provides three modes of exposure control: fixed, extended and hyper. I chose to use the fixed position, which allows you to set short exposures from 1/100 of a second to 1/12,000 of a second. The setting can be controlled directly using the menu buttons on the back of the Xtreme. This mode allows you to image daytime objects and the Sun. It is also appropriate for use on the Moon and the brighter planets.

The extended mode allows you to do longer exposures from 1/30th to 2.1 seconds in fixed stops for imaging fainter planets and bright stars. I will address this mode in my next article using my Meade LX 200 14-inch ACF and LS 8inch ACF. Hyper mode allows you to perform exposures from 3 seconds to 99 minutes.

In this mode, the Xtreme needs to be controlled by an external unit. If you want to control the Xtreme manually in this mode, you will need MallinCam’s optional wired keypad (Image 10).

Pushing the buttons on the back of the Xtreme will likely cause vibrations that ruin the long hyper-mode exposures.

Image 11 - A live image of the Sun on the author’s Sharp 32-inch TV monitor.

The Xtreme allows you to set and control the hyper mode by attaching a cable to the RS 232 port on your PC or laptop. MallinCam notes that there are several software packages available that offer all control options – some are free, while others are fee-based. Software alternatives are listed in its website section, “Controlling the Xtreme using software.”

Controlling the Xtreme

by Hand You can use the Xtreme in the field without attaching it to a PC or laptop.

This reduces the number of cables needed. As noted, you can control the Xtreme manually two ways: (1) pushing the buttons on the back of the Xtreme or (2) using the optional remote wired keypad (Image 8) without actually touching the buttons on the back of the Xtreme.

The Xtreme also has a 4-pin socket mounted on one side for connecting a wireless exposure-controller receiver.

On the rear of the camera, between the Composite and S-Video outputs, is an 8-pin RS-232 socket. It is labeled “AUX.” This rear socket can be used to connect another option – the complete control cable for controlling all aspects of the camera, including menu and ex-

posure – or it can be used to connect the wired keypad. The keypad must be used in conjunction with the wireless exposure control installed into the side camera socket. Without it, the Xtreme will be limited to 2.1 seconds. The menu can be controlled with the buttons on the rear of the camera or through the use of the wired menu keypad.

Setting Up for Solar Viewing I was ready to attach the Xtreme to my 90-mm SolarMax. I aligned the SolarMax on the Sun, focused it and adjusted the Etalons for the best exposure to my eye. I made sure the Xtreme was off by unplugging the 12-volt connector.

I connected the focal reducer parts shown in Image 9 and attached them to the Xtreme, then attached the camera to the diagonal of the SolarMax and plugged in the Xtreme.

Should the image from the Xtreme start blinking or flashing, it is a green screen because the Xtreme is sensitive to light and may trigger a safety that will prevent overloading the electronics. Just unplug the camera for about five seconds and reconnect. Wait three minutes for the electronics to settle and change the exposure setting to eliminate a reoccur-

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OBSERVING THE SUN IN COLOR WITH THE MALLINCAM XTREME – PART 1 rence. You will need to set “sense up” to “off ”.

If you are using a laptop or PC, set the video mode using Miloslick, a software package available for $49US at www.miloslick.com. when you are doing your viewing. Set AGC to “off ” and set ALC to 1/12,000 seconds in exposure when using the Miloslick software.

The Xtreme user’s manual gives all the detailed instruction on setting up the camera. You can download a copy of the manual from the MallinCam website.

The manual covers problems you may encounter during set up and has cures to overcome them.

Tuning the Ha Filter Page 98 of the user’s manual covers menu settings for viewing prominences.

It gives you the right tune-up for adjusting the Ha filter to make prominences stand out. Adjust the red and blue to enhance or decrease the image of the prominence. As the manual warns, it is very important to make sure the AGC is set to “off.” I set the shutter to 750 to get the best contrast ratio on the live monitor.

Setting APC for Live Observation/Imaging APC stands for “advance pixel control” and is an enhance-mode feature for live observation. When viewing the Sun in Ha, use the APC from the halfway point to near full. Careful adjustment of APC will outperform any camera as far as resolution is concerned. Live observing is set with the APC adjustment in the middle position to give you high resolution on your TV or monitor.

Setting AGC The Automatic Gain Control (AGC) mode has three options. Placing the cursor next to AGC, press the right or left key and you can toggle from on, manual and off. As noted, always use the off position for solar viewing.

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The Payoff So, after all the careful setup, what can you expect? Plenty! For starters, you can see detail on the photosphere of dark lines, which are filaments (prominences.)

When prominences are at the edge of the photosphere, they stand out where you can see the gases extending above the photosphere/chromosphere at the limb of the Sun. You can also see plages, which are bright patches in the chromosphere that are higher in temperature then the surrounding area.

The Xtreme performed flawlessly in my observatory. I should have no problems using it in the field with my Meade LS 8-inch ACF attached to the LED TV monitor. For field use, you need to use the wireless exposure controller or wired keypad, which are optional, or use a laptop with the software needed to operate the Xtreme.

On the pro side of the review equation, the Xtreme camera is extremely small and lightweight. All told, it’s also easy to set up and use, and it produces brilliant images on an HD TV screen.

Its cost is reasonable, and I’m aware of no other video cameras currently available that can show equal detail of the Sun. On the con side, the camera itself does not have an industry-standard HDMI port, something I’d like to see in future versions, although the upscale unit does have an HDMI port. Also, it’s likely that you’ll need a portable generator if you use a standard TV monitor in the field away from electrical outlets.

In conclusion, MallinCam offers a full range of video cameras, one of which is sure to fit your specific application.

Whichever you select, I know of no other device to better enhance your ability to share enthralling live images of the Sun. Bottom line: MallinCam is, to my knowledge, the most advanced video camera for live observational solar viewing in color.

OPTICAL TESTING SERVICES

RECOATING SERVICES

Test Package 1: Optical Quality Assessment - Includes the FoucaultNull (double pass) and figure of revolution (astigmatism and flexure) tests. Test Package 1 will detect errors on asymmetry, check for surface smoothness, check for overall correction and detect zonal errors in the optical figure.Test package 1 can be preformed on both coated and un-coated optics.

The Process - We strip old coatings and center spot at no additional charge (check with us for choices available). We use a dilute solution of hydrochloric acid and copper sulfate to remove old coating.This solution safely removes the old coating without affecting the underlying glass or optical figure. This method has been used safely for years, it is gentle but is effective on aluminum and the over-coating on top of the aluminum. Our cryogenic systems consistently produces first rate coatings each and every time. In side by side comparisons, our coatings are brighter and more brilliant than the competition.

We can test your mirror and provide you with a reliable analysis of its wave front quality. We offer two test packages and all testing services include a telephone consultation to discuss the results once testing is completed.

Test Package 2: Quantitative Interferometric Assessment - Provides a full quantitative analysis of your optics. Your mirror will receive all tests included inTest Package 1 and then undergo interferometric testing. When testing is complete you will receive a full test data report that includes values for astigmatic error, Strehl ratio, RMS wave front error and peak to valley wave front contour map. This test package can be performed on both coated and un-coated optical surfaces. We can interferometrically test to f/3.

Concerning Interferometry - We test, collimate, and clean most telescope optics and OTA’s (optical tube assemblies). Our state of the art software is concise and accurate. Employing Shack-Hartmann wavefront analysis (using a test bench or a star), your optics are collimated to realize their full potential.

This procedure will also reveal other issues that may be present. We are not here to challenge “other” manufacturer's claims but rather to super-tune your optics to get the most out of them. You'll know if you should expect diffraction-limited performance.

We use our state of the art cryogenic systems to apply 96% multi-layer (4) enhanced Aluminum coatings up to 36" diameter. Standard Aluminum coatings are available upon request.

44" Cryo Cooled Hi-Vac Coating System - Our system features a humongous 20" CTI cryogenic helium cooled high vacuum pump.

This is the second cryogenic helium cooled high vacuum system in our shop. We offer you a convenient alternative for getting your large optic recoated and we welcome hand deliveries of your precious optics if you choose to bring them to us.

PRIMARY OPTICS

FUSED SILICA BLANKS

We are a full time optical manufacturing company that specializes in proto-type development and small production runs. We manufacture precision Parabolic, Spherical & Flat optics of any size or shape, up to 25" diameter.

Fused Silica Blanks - This material is harder than Pyrex or Supremax with a much lower coefficient (near zero) of expansion making it ideal for use in imaging systems. Base prices are for plano/plano blanks and curve generation. Hole drilling or any other modification is available at additional cost. We offer blanks from 12.5" – 25” with most blanks are in stock. Larger sizes are available for special order and discounts are available for orders of four or more. Every blank is tested for proper anneal before we ship it to you.

Astronomical Optical Sets f/4 - f/6 - Custom optics sets are made from precision annealed Supremax brand glass. A secondary diagonal will also be supplied, made from fine annealed Supremax. All optics are serialized and interferometric data is supplied with each. Our enhanced aluminum coatings are included.

We offer Fused Silica blanks which are the same blanks we use in our production.

Fast* f/3.5 Astro-Imaging Optical Sets -These optical sets are manufactured from thermally stable Quartz (fused silica) substrates and are best suited as astro-imaging optics. Our Quartz blanks have excellent coefficient properties with precision anneal.

We can make you a set of Quartz optics in any size and focal ratio.

Secondary diagonal will also be supplied, made from Quartz substrate. All optics are serialized and interferometric data is supplied with each. Our enhanced aluminum coatings are included.

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The Astro Hutech Hinode Solar Guider

Image 1 - The Hinode kit as shipped from Astro Hutech, minus the mounting base, of which there are three options.

By Austin Grant

In the realm of astronomy, there are several “first” that are sure to leave people speechless. Being involved in astronomy outreach, I can tell you that one of the most notable ones is the first time a viewer sees the rings of Saturn. Words usually can’t describe that sense of awe and wonder. Another is the Great Red Spot on Jupiter.

We’ve all seen it in pictures, but to observe it directly is an amazing experience.

Galilean moons, Iridium flares, and the International Space Station would also make the top of this list. For me, one event trumped all others, and has remained at the top of my “firsts” list: I’ll never forget my first view of the Sun through a hydrogenalpha telescope. Being an imager at heart, I knew instantly that I needed to be able to take images of the Sun. This, unfortunately, led to more of my “firsts,” and not ones I’d

be happy to repeat.

The first time I tried to image the Sun nearly became my last time to image the Sun. I didn’t yet have a hydrogen-alpha scope, so I started with a white-light filter. It was a full-aperture filter for an 8-inch SCT; quite a bit of focal length for a beginner. To make matters worse, I only had an old dualaxis driven Celestron CG-5. The nail in the coffin was the gusty winds, exaggerated by a bad polar alignment and a tiny CCD sensor. I spent all of my time trying to keep sunspots centered on that CCD sensor, battling drift with the hand controller the entire time. When the processing was done, what had initially been a small field of view resulted in almost nothing to show. The stacking process works best if you crop to sections that are in all frames, and in my case, that was basically nothing. Much more

luck like this, and I’d have given up for good.

Fast-forward to NEAF 2014, when I walked past the Astro Hutech booth where something new and interesting caught my eye. On display was the new Hinode Solar Guider, a stand-alone autoguider designed for visual observing as well as photography.

I was immediately back in that first solarimaging endeavor, and a chill ran down my spine. Sure, I’ve upgraded equipment since then, but some of those main problems will occur regardless of the gear used. Still, this Hinode was a promising tool, so as soon as they were available I picked one up.

The Hinode Solar Guider from Astro Hutech arrived in a cool plastic case, with all the components you need to immediately get up and running. To be specific, that includes the optics/electronics assembly box, Astronomy TECHNOLOGY TODAY

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THE ASTRO HUTECH HINODE

Image 2 - The Hinode optics/electronics assembly box with course Image 3 - The Hinode hand-controller hanging on a Celestron CGE equipped with ADM Accessories anodized knobs. finder mounted on a Celestron 11-inch SCT.

hand-controller, USB cable, hand-controller cable, autoguider cable, and choice of mounting base. There are three mounting bases to choose from: Universal, Lunt and Coronado. I went with the Universal base, but also added a Coronado base to use with my SolarMax II 60-mm H-alpha scope.

The fit and finish of all the parts and accessories was fantastic. The optics/electronics box was metal, as were the mounting bases. The hand-controller was made of durable plastic, so it was both strong and

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lightweight. Everything looked great, but I wanted to know how it set up and worked.

The Coronado mounting base was a snap to install. I simply removed the Coronado Sol Ranger from the clamshell and installed the Hinode base in its place. As for the Universal mounting base, I had several options for using it. It is designed to fit into a standard Orion/Synta-type finder shoe, but none of my gear had one. Instead, for whatever reason, my 8-inch Meade SCT, 11-inch Celestron SCT and ED80 all had

different aftermarket finder attachments.

Luckily the Universal base has bolt holes and a slotted bottom, so making it work with each of these scopes was a snap.

Once I was able to mount the optics/electronics assembly box on any scope, I attached the hand controller. It has a nice loop at the top, and my ADM Accessories knobs on the Celestron CGE came in very handy as a hanging point. Finally, I had to connect the Hinode to my autoguider port and add power. The kit includes a

THE ASTRO HUTECH HINODE USB power cable, which will probably work well for any imager, because you will already have a computer nearby. If you are using this visually or imaging without a computer, it needs a 5-volt DC power supply.

With everything connected, I was ready to go. At this point, I should tell you that my Celestron CGE is mounted on a concrete pier inside my observatory. I decided to test it there before going mobile. Because I was already polar aligned and on a sturdy setup, I wasted no time in going straight to my most challenging scope. I mounted the 11-inch SCT and started up the computer.

To actually capture images, I used the QHY5L-II from QHYCCD. The magazine has covered this camera before, and it still amazes me with its high frame rate and high-quantum efficiency sensor. With everything ready to go, I powered on the Hinode.

To begin, I pressed the Finder button on the hand-controller, putting the Hinode into Finder mode. There is a coarse finder on top of the optics/electronics assembly, where the Sun will appear centered in a yellow circle when you are close. Once you get close, there are five directional LEDs on the hand-controller, with four outside of a centered LED. As you approach perfect center with the Sun, the outer LEDs indicate the direction you must move the scope. It was a very intuitive process and took less than a minute to accomplish. If you are unable to see the hand-controller while centering the scope, you can press the Finder button again to activate audible feedback. Here, the pitch increased as the Sun was centered.

The next step was to calibrate the autoguider. The instructions mention that the guide rate should be set to a low speed, but mine was already at 0.5X sidereal, so I left it alone. I simply pressed the Calibrate button and let it do its thing. The LEDs indicated which axis and direction was being calibrated, and after about 90 seconds it returned to Finder mode. From there, all I needed to do was press the Guide button, and I was off to the races.

A cool feature I discovered after the fact was that you can save the calibration for a

Image 4 - The Hinode kit is shown mounted and in operation on a Celestron 11-inch SCT and CGE mount.

quick startup. There are two memory positions, one for AM and one for PM. To save a calibration, simply hold down the appropriate button until a tone is heard. Then, for a quick start, from Finder mode simply press Recall and the appropriate AM or PM button. Then you are ready to guide.

The installation was easy, the setup and calibration was a breeze, and the Hinode certainly looked cool as it attempted to keep the Sun centered on my camera sensor. But how did it work? Iâ&#x20AC;&#x2122;ll offer sup-

porting details in a second, but I can sum it up with a single word: Brilliantly!

With the 11-inch SCT on the already polar-aligned mount, I was mainly doing battle with periodic error, sidereal-vs-solar tracking rate, and any residual polar misalignment. Using the full focal length of the scope and with the sensor cropped to 640x480 pixels for maximum frame rate, an unguided image of the Sun would drift completely out of the frame in less than two minutes. Turns out my polar alignAstronomy TECHNOLOGY TODAY

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THE ASTRO HUTECH HINODE

Image 5 -Sunspot captured at a focal length of 5000 mm with a QHY5L-II CCD camera through a Tele Vue 2.5X PowerMate and 8-inch Meade SCT, guided by the Hinode.

Image 6 - Another sunspot captured at a focal length of 5000 mm, guided by the Hinode.

Image 7 - Yet another sunspot captured at a focal length of 5000 mm, this one in false color, guided by the Hinode.

ment wasn’t as great as I thought! Once I activated the Hinode for autoguiding, sunspots stayed centered indefinitely. There was some minor jostling around, but it can be attributed to scintillation. I couldn’t believe how well the Hinode worked! Still, seeing was poor, and I didn’t get any publishable images from that outing.

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On my next outing, I removed the CGE from the pier and mounted it on a tripod in the backyard. This more closely resembled most of my solar outings, where I just plop the mount down and point it approximately north. This time, I mounted the 8-inch SCT, but added a Tele Vue 2.5X PowerMate to the mix. That’s

Image 8 - Coronado SolarMax II 60 Halpha telescope mounted on a Celestron CGE, equipped a QHY5L-II CCD camera and Tele Vue 2.5X PowerMate, ready for guiding with the Hinode.

5000-mm focal length on a non-polar aligned mount! I measured drift without guiding, and it was absurd. Again, after activating the Hinode things were just…there - right in the center, and they stayed there.

If I’d had this kind of gear from the beginning, perhaps I’d be giving Stephen

THE ASTRO HUTECH HINODE

Image 9 - H-alpha image taken with the QHY5L-II, Tele Vue 2.5X PowerMate and Coronado SolarMax II 60, guided by the Hinode.

Image 10 - Another H-alpha image taken with a QHY5L-II, Tele Vue 2.5X PowerMate and Colornado SolarMax II 60, guided by the Hinode.

Image 11 - Full-disk (almost!) H-alpha image captured with the QHY5L-II and Coronado SolarMaxII 60, guided by the Hinode.

Image 12 -An inverted version of Image 11.

Ramsden advice on solar imaging! (By the way, my friend Stephen Ramsden is the driving force behind the Charlie Bates Solar Astronomy Project, likely the largest solar-outreach program on Earth). Seriously, though, the Hinode just plain works, and it’s simple to use. I got some nice sunspot images with excellent detail for my modest equipment.

For the next few outings, I used the Coronado SolarMax II 60-mm H-alpha telescope. I used it with and without the TeleVue 2.5X PowerMate, and

with the QHY5L-II in both full-frame and cropped mode. Because of the Hinode, the images were magnitudes more stable than ever before. More of the data could be stacked, and I ended up with more of my original resolution than I’m used to. The Hinode truly has made solar imaging more effective, and more fun.

The Hinode Solar Guider from Astro Hutech has turned out to be one of my favorite astronomy tools. It has eliminated all of the controllable sources of frustration from my solar imaging workflow. I no

longer need to struggle with a compass and polar-offset charts in an effort to get perfectly polar aligned in the daytime. I no longer need to struggle with the mount hand controller, trying to compensate for drift, periodic error and backlash. All I do now is set up the mount and scope, attach the Hinode, and start imaging.

If you find yourself dealing with any of these issues during your solar outings, and I’ll bet you do, then the Hinode Solar Guider is surely a tool you need to check out.

Astronomy TECHNOLOGY TODAY

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ONE HALF OF THIS IMAG GE WA AS TA AKEN WITTH A $2,499 ESPRIT

THE O OTTHER WA WAS TA TAKE K N W A SCOPE THAT WITH AT COSSTT TWICE AS MUCH Actually, the other telescope cost more m than twice as much as the Esprit, but that’s not really the point. The point is, do you see twice as much performance on one ne side of the page than the other? Taake a close look.

Are the stars twice as pinpoint?

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© 2 017 S k y-Watcher U S A . S pecific ations subjec t to change without notice. 2 0 -170 01.

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Imager: Jeerry Gardner of Fort Worth, Teexas (Three Rivers Foundation Volunteer) OTA A 1: Skky-Wattcher Esprit 100mm EDT f/5.5 OTA A 2: World-c o lass 106mm f/5 astrograph Mount: Taakahashi a NJP Guiding: Orrion SSAG Magnificent Mini AutoGuider Camera: Caanon 60Da Exposure: 988 light frames @ 360 seconds each. each 411 dark frames, 100 bias frames and 30 flatts. t Processing: PixxInsight. Identical processing for each imaage.

If you don’t think so either, perrhaps you should consider purchasing a Skyy-Watcher Esprit triplet. At Sky-Watcher USAA we pride ourselves on offering products with ith worldclass performance at affordable ble prices.

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Starting at only $ 1,6499, the Esprit line is offered in 80, 100, 120 and 150mm appeerrttuurrees anndd comes complete c with a 9 x 50 right angle finde derscope, 2-inch Star diagonal, 2--element field flattener,, camera adappteer, mounting rings, dovetail plate and foam m-lined hard case.

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Plus you still get all of Evolution’s most desired features: + Fastar/ HyperStar compatible + 10-hour rechargeable lithium iron battery for ultimate portability + Convenient design features including manual release clutches and precision machined worm gears for both axes, USB charge port, tray lighting for your accessories, and more

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