Magnitude 001 issuu sept 2015

E D U T I N G MA

Every Month!

September 2015

magnitude@darkframe.co.uk

Would you like a quieter Mount? ‘Ambient’ Tuning Explained New Enhanced Handsets from Skywatcher To Guide, or not to Guide?

Innovative new products from Bodai-Global QHY5-II Range Investigated

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E D U T I N G A M Contents New Products Ambient Tuning To guide, or not to guide?

Intoducing Bodai-Global QHY5 Investigated Customer’s images Next Month’s issue

p4 p5-7 p8-9 p10 p12-14 p15 p16

Subscribe & Contact David Woods - Editor & Publisher DarkFame Ltd www.darkframeoptic.com MAGNITUDE Editorial David Woods - magnitude@darkdrame.co.uk Web Site: - www.magnitude-ezine.co.uk Tel: 023 9257 0283 Skype: DarkFrame Post: HantsAstro.org 11 Drift Road, Clanfield, Hants PO8 0JJ This Newsletter/eZine is published on behalf of the DarkFrame Ltd. Any opinions and views expressed in this publication are not necessarily those of the Editor, Publisher, Sponsors or Advertisers of DarkFrame Ltd Magnitude. Where Links take you to other sites, the Editor, Publisher and Webmaster cannot be held responsible for the content of those sites.

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Dave Woods Editor & Publisher Hello and Welcome to our first issue of Magnitude!

It’s a newsletter, but also it’s not. We like to do things a bit differently here at Casa DarkFrame.

Yep – we sell stuff and you know that. For us though what we really love is what astronomy gear can do and what it does for you as an astronomer. The thing is we found out that there’s much more room for improvement in how mounts and telescopes work.

Which leads me neatly (and quietly) to what we term ‘Ambient tuning’.

We’re finding many owners want an experience of touring the night sky without the serenity being harshly interrupted with the gnashing, grinding cacophony of a dual axis mount on a fast slew. It would be like listening to J S Bach on Classic FM then suddenly Motorhead Lemmy screaming out Ace of Spades as your telescope gracefully glides to Messier 13.

For those of you wanting more performance then belt drive upgrades are the way to go. Eliminating backlash in any worm mount is one of the best ways to improve accuracy. We’re also taking a look at guiding as people progress from widefield DSLR imaging, in our Astronomy group HantsAstro, and move to longer exposures.

Another element of better guiding is optimal balancing and polar alignment so you should check out the innovative products from a new company called Bodai-Global. They have a whole suite of new products coming out over the next few months which we will be covering and that will make your astronomy easier and more reliable in terms of imaging and observing.

DarkFrame is part tuner, part bespoke telescope manufacturer and dealer. As astronomy is changing in the UK (and throughout Europe) we are providing ways of bridging the gap between entry level astronomy and the higher end performance offerings that are out there.

I’m sure you’ll find this as interesting as we do

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New Products!

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Here are some new products from our webstore: 1. BoDai-Global Polarite 1x2.5x polarscope adapter. Polar aligning is no longer a pain in the neck! - £72.00 2. Sky-Watcher Enhanced Handset with Autoguide port for EQ3-2/EQ5 £84 handset / £120 motor kit 3.Watec 902H2 Ultimate Sensitive Mono Camera for Solar/Lunar video work with great detail - £249 4. BoDai Global CloverThree Travel counterweight for Star Adventurer in Red - £37.00

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MAGNITUDE Feature

One of the first cars I owned

was a ‘hearing aid’ beige mini Metro, 1.0 L circa 1983. It had skinny little wheels, wind up windows and a big steering wheel. What I loved about the car was it’s simplicity and the fact that it ran like a Swiss watch. As a modern replacement for the Mini – it was almost as much fun.

But my first car was a Volkswagen Beetle, with no head lining, no carpets and an exhaust that would make your ears bleed. I loved that too but my neighbours didn’t. Just as using a mount at midnight in your back garden can carry a bit of an ASBO risk if it’s grinding away slewing across the night sky.

Dobsonian GoTo set ups can be very loud as some of their owners have found out. Now

Would you like a quieter Mount?

in a large field with other astronomers this isn’t much of an issue, but if you’re narrow band imaging from your garden and your neighbours can hear you, then that could be a problem.

One of our customers gave us his SynScan AZ mount to quieten down as he considered it ‘too noisy’ to use and wanted to know if we could do something about it. We decided to sacrifice our own demo SynScan AZ mount to see what we could do.

Now noise is quite a subjective thing. Like my Volkswagon Beetle that sounded like a Harley Davison, with its exhaust notes bouncing off adjacent buildings. It may have been entertaining during the day and barely acceptable, but at night it made me none too popular.

The ambient noise level of where you live changes during the day. In a suburban area

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cont’d - your mount will read about 10 to 15 decibels louder but at night – depending where you live – the noise floor drops considerably. This is down to a number of factors. For those of you that live in the countryside you’ll know what I’m talking about, it’s more peaceful. But during the day in built up areas traffic noise, TV’s, radios and people just generally living all contribute to this level.

It’s true what they say about silent night unless you live in the city. So taking out wind noise your mount will emit certain frequencies which carry over distance and during the day they can be 10 to 20 decibels higher than ambient, but at night they can be up to 30 decibels higher. It’s not that the mount has become noisier it’s just that at night time it seems louder because everything else is quieter. Each 10 decibels of noise is effectively double the amplitude in human hearing terms.

What we do is service and adjust the mount so it runs more smoothly and therefore, quieter. We measure the primary sound signatures then make the necessary adjustments and lubrication to reduce certain frequencies that provide the most trouble.

As far as we know we are the only tuning business to do this. When we were developing this, we discovered that the results were staggering – look at the two graphs (before and after).

Overall all frequencies are reduced by up to 10 to 15 decibels, but in particular the lower frequencies (which are produced by drive train operation) are the ones that we focus upon as they provide greater resonance.

There are a number of techniques that we employ to reduce this – and this is mount dependant. Indeed, almost all astro imagers have commented on how quiet their belt drive HEQ5’s and EQ6’s are after we’ve

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Would you like a quieter Mount?

upgraded them. Where applicable we will fully rebuild gearboxes and provide motor isolation if the customer wishes an even quieter mount.

Most of our Ambient tuning is around AltAz mounts and increasingly old EQ mounts like Meade LXD55/75 and Celestron CG5GT’s which are particularly noisy. We have also rebuilt Celestron CGEM gearboxes with success as those gearbox stacks are quite noisy by nature.

Reduction gearboxes increase noise.

The main culprit of most of these sound issues with these motors is not the motors themselves it’s actually the gearboxes.

The motors themselves will spin from 3000rpm to 5000rpm during a fast slew. The gearboxes, because of their construction and gearing, will generate a large amount of noise.

We are able to reduce this.

Because of the development and success we’ve had with these we are now extending our warranty from the 1st August - from 90 days to 1 year on Ambient tuned mounts.

Because the mounts are effectively serviced at the same time - we would advise and recommend where improvements can be made by the fitment of new parts. Ambient tuning starts at just £69 including vat, for a small AZ-Goto mount rising to £199 for a larger mount, depending on the work required. We aim to reduce the mount noise by a minimum of 10 decibels and provide before and after wave form graphs to demonstrate the improvement made.

As part of our on-going R&D we catalogue every service and re-build photographically at each step so we can continuously improve the performance of these mounts.

Cont’d

Lubrication is just part of the solution, or in this case not...

Isn’t this all just ‘snake oil’?

Actually the original snake oil worked – all the rest of the stuff was fake. The different here is that we provide measurable benefits to any claim we make and of course, you should be able to tell the difference yourself!

Now some dealers and importers will go as far as to renounce the benefits of what tuning a mount can do. But these instruments are mechanical and do require maintenance, they are not all sealed for life and therefore, they are not maintenance free.

If you want to protect and prolong the investment of £100’s or £1000’s you’ve made on a mount then you do not have to go the expense of overhaul to a main supplier.

How often would my mount need servicing?

That depends on how often you use it and how you store it. We would advise that any mount unused in storage should be serviced prior to use and thereafter, every two years.

If you leave your mount outside or it’s used in damp conditions, then we suggest you bring it in annually for an assessment – which is free of charge. If it doesn’t need servicing we’ll

tell you but you should be able to see some degradation in either noise or tracking as a warning sign.

Can I service the mount myself?

You’re more than welcome to have a go.

However, this carries risk. We use the correct lubricants that either meet or exceed manufacturers specifications in terms of lubrication and dampening. To use a car analogy – if you’re happy to rebuild your engine and gearbox – then go ahead!

For the others out there we have a proven track record of reliably enhancing practically any type of mount.

Plus we also carry and can obtain genuine spare parts, as well as being able to manufacture bespoke, modified parts in house, using CNC machining and CAD/ CAM Design.

For further details and information please either visit our website: www.darkframeoptics.com or call us on 023 9257 0283 DW

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To guide, or not to guide?

You can read about

QHY5 auto-guiders elsewhere in the Newsletter, but first off the question should be - Do I really need to AutoGuide?

Largely this depends on a number of factors including what type of imaging you want to do. I do a lot of wide field imaging so mostly my focal lengths are less then 300mm, which is much shorter than some of the smallest refractors even with a flattener/reducer.

But as the focal lengths get longer and the apertures get bigger as you move into deep sky, auto-guiding becomes essential. If you have a telescope over 750mm in focal length and you want to go beyond 30 seconds exposure, then the need for guiding will become apparent.

With compound telescopes like Maksutovs and SCT’s – if you’re doing planetary then doing quick bursts of video with something

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like a QHY5-IIP is, for only £159, a killer setup. I’d go for the 150mm SkyMax and not the 180 – I’ll explain why in a future article.

With the cost of auto-guiders coming down in price, even guiding for wide field makes sense as it allows you to run much longer exposures. Think of auto-guiding as an insurance policy – sure you have to get good polar alignment - and there’s no excuse for not doing so, however, with a dualaxis motorised GoTo mount auto-guiding provides you with a form of insurance policy. It raises the bar where it’s as good as ‘drift aligning’ your mount but without wasting your time trying to get perfect polar alignment.

Paralysis Analysis.....

Push here Dummy (PHD Guiding) is one of the most popular software programmes to use with guide cameras, but many imagers

This is what Auto-guiding is all about. Following precession. over emphasis the need for good, flat graphs.

A lot of this is down to the build quality of your mount, as most RA and DEC set-ups aggressively track the guide star effectively where it’s hunting and the mount over responds to the guide command.

The defaults on both axis are set at 100%, but try reducing this on an NEQ6 - ideally it should be set somewhere between 50% and 70%. What a lot of people don’t do is to use the software to calculate what the setup should be – and therefore calibrate the motions required for guiding. Once set up you’ll find that PHD will provide you a great platform for controlling your mount.

Considering that ‘seeing’ conditions in the UK is circa 2Arcseconds is about the average then trying to guide your stars below this can be somewhat academic. The important thing is to work within the parameters of your mount and not trying to force it to do something it can’t. Most mounts will easily guide down to about 2 Arcseconds with a little tweaking, but belt-driving and tuning the mounts just make your guiding much easier and more reliable. If you’re doing 10 to 15 minutes images and you lose one or two an hour then that’s far more painful than losing one or two images at 5 minutes.

Why do we need such long exposures?

It’s all to do with signal to noise ratio.

Even with cooled cameras – I’m not talking just about the noise in the cameras themselves, but moreover the amount of light that can be gathered by a sensor over time.

With longer exposures each pixel on the sensor absorbs as much light as possible, this is of course balanced by the performance of the chip itself. But here this is where CCD’s win out over their DSLR counterparts, to make the most of your sensor longer exposures (up to a point) are much of a muchness regarding in terms of detail. That, my friend as you’ll discover is down to your processing...

Thing is, even with 5 minute images, you’re likely to get something flying into your shot, especially if you live within 40 miles of a busy airport, but in the UK at least, the skies are a lot less busy after 9pm if you live in the South-East.

So, to guide or not to guide?

If less then 300mm and 3 minutes?

No. If less than 500mm and 1 minute 30 secs – then again, no. But anything over this then guiding is advantageous and the rewards amazing. Just check out a few of our customers images on page 15.

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Introducing BoDai-Global

UK Innovation allied to rapid prototyping means faster solutions BoDai Global. This strange sounding company that invents its own products not just for Astronomy but in automotive and other interests as well.

With in-house CNC engineering facilities it means that they can take an idea and put it through their design and prototype process that mean they come out with a solution to a problem, that’s neat clever and original.

Astronomy suffers from a lot of ‘badge engineering’, but this company seeks out new ideas, not just rehashing old ones.

The Cloverweights is one of their first products released, along with the Polarite right angled viewfinder for your polarscope, and some new products for your DSLR camera.

Also in the pipeline is a range of levelling base for your GoTo Dobsonian which helps with point accuracy, along with new products that will feature in future issues of MAGNITUDE. Each project is becoming more sophisticated than the last.

As such, if you think you have something as either a one-off, or an ideas that could be useful for astronomers? Then get in touch with Bodai-Global. ideas@bodai-global.com

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Authorised Dealer | Servicing & Tuning Specialists

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We’re all that you need to get the most from your Astronomy.

023 9257 0283 Find us on:

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d e t a g i t s e v n I e g QHY5-ll Ran

It’s that perennial question you get when you

realise that you want to go longer and deeper in astro imaging. However, going longer and deeper sometimes means you can be disappointed with the result.

evolved from the original QHY5’s reputation with even better sensitivity and higher frame rates making them ideal candidates for Lunar, Solar and Planetary imaging, as well as some basic deep sky stuff.

It’s a bit like cars. We all drool over the Lamborghini and Ferraris then climb back into our Ford Fiesta and drive home. While the latest liquid cooled, no noise, highly sensitive mono camera with a 7 colour filter wheel may prove to be ultimate weapon of choice. For many of us starting out though, having a dual purpose camera makes far more economic sense.

There are 6 models in the family, and all have their pros and cons. But the popular 3 are the QHY5-ll-Mono (£199), QHY5L-ll-Mono (£229) and the QHY5-ll Colour (£135). The Mono is touted as being better for guiding duties as it’s more sensitive. This depends also if you want to experiment with filter wheels. In good old Blighty the general trend is towards colour cameras at the moment, due to our changing weather patterns and the time it takes to gather multiple sets of data from a mono camera.

Guiding is all about the focal length of your telescope versus your exposure time, which leads me quite neatly onto these lightweight QHY5 ll cameras. At circa 45 grams these featherweight tubes of technology have

A lot of my personal imaging is based around an F4.8 72mm refractor so my need for guiding really only comes into play on an EQ mount after about 3 minutes. Once you move away from wide field imaging and start

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imaging with focal lengths over 750mm with longer exposures over 120 seconds (assuming your mount can handle it in the first place), then guiding is a must.

On mounts like the Celestron CG5/AVX then guiding as well as good polar alinement will help you achieve exposures of between 5 to 8 minutes and similarly with the SkyWatcher venerable HEQ5. 10-20 mins for an EQ6...

Regarding the cameras any of them can be used for guiding quite successfully, using anything from a 50mm aperture finderscope through to a 70mm or 80mm refractor. The bigger the aperture the more reliable your guiding should be. If you think about it using PHD you’re effectively trying to follow procession so you need a decent star to guide upon.

Sometimes you’ll have to guide on a feint star close to the object you’re imaging, which means sometimes getting down to 11+ magnitude and this is where good aperture and a high QE helps in terms of reliability.

This is where the Mono Camera excels.

QHY5’s have a proven track record, which is reassuring given number of recent apparently cheaper autoguiders coming onto market.

So without spouting loads of physics we’ll just apply some simple logic. The greater the light gathering your guide camera has – then you could in theory get away with a simple webcam, but it will lack the detail and resolution of a decent CCD camera.

We picked the QHY5 range of cameras because even though their specs may not set the world on fire compared to their more expensive brethren, but they work. You can’t get a Fiesta to Jupiter and back either.

Not starting from £135 anyway...

The QHY5-II range are the benchmark for small CCD guiding and imaging

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Camera Comparison Altair GP-Cam Col Altair GP-Cam ZWO ASI120MC OpticStar PX-125C Mono ZWO ASI120MM (GCMOS series)

CMOS Sensor Aptina AR030 MT9M034M Aptina AR030 MT9M001 (Mono)

Full Resolution 1280x860 1280x960 1280x960 / 1280x1024

Imager Size 1/3” 1/3” 1/3” / MM 1/2” Max FPS on full resolution

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30

30/30

Max FPS on 640x480 30 (100 GP-Cam) 100

113/100

Pixel Size (µm)

3.75 / 5.2

3.75

3.75

Peak QE 74% 74% MC75% / MM55% Price

£135/£129 £135 £225/225

QHY5-II Conclusion Compared to other offerings in the market for guiding/imaging the QHY5 in many of it’s guises - sits in the middle.

Essentially an auto-guider is all about tracking a selected star reliably and in this respect any of the cameras above would suffice. However, the QHY5 range has been around for far longer and now comes with a reassuring 2 year warranty.

Because QHY recognise there is no ‘one size fits all’ approach, the six models they offer provide you with a choice of how you’d like to get into auto-guiding/entry level CCD imaging.

There are also optional QHY premium packages and no ‘hidden’ costs in what you’re getting, so take care when comparing like for like costs.

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What appears to be a bargain can soon add up when you factor in accessories like IR filters and lenses, or a specialised guidescope, for instance.

QHY cameras also boast a large user community so it’s easy to find a solution to any problem you might come across.

Sensors should mostly perform the same so but costs are often cut by using cheaper or even omitting components. How they are driven in software also counts.

Like most things in life you get what you pay for and QHY still remain a trusted benchmark of value versus performance, especially when you take ease of use and support into the equation. Of course, that benchmark may shift again when the QHY5R-II hits our shores.

DW

s e g a m I r u Yo

Cocoon Nebula IC 5146

- Paul Beacham

01-Aug-2015, Hampshire UK Altair Astro 102EDT Atik 428EX Mono/Ha Filter NEQ6 Mount

24x5mins, Guided in PHD, Bias/Darks/Flats applied.

Stacked in Nebulosity 4.0 Processed in Photoshop

Elephants Trunk IC 1396A

17-Jun-2015 Berkshire, UK Altair Astro 80EDT SX694 Mono/Ha & OIII Filters NEQ6 Mount

- Martin Baker

9x20mins HA 8x20min 0III, Guided in PHD with Lodestar

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NEXT MONTH* In October we look at the need (or not!) for big aperture telescopes, photo exploits with a Sky-Watcher Star Adventurer, and a new series of examples of what’s going on when your images don’t quite come out the way you want, and how to fix it.

We’ll show you what you get from belt-driving a Sky-Watcher NEQ6, along with an overview of what to look for when buying secondhand.

Also, several new products to help you get more from your Astronomy, as well as Your Images, so please keep sending them in! Thanks for reading! * Editorial content subject to change.

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