FOG HORN
July 2019 Twobirds Flying Publications
Vortex Razor HD 4000 Laser Range Finder Copyright 2019, Towbirds Flying Publications. All Rights Reserved.
Vortex Razor HD 4000 Laser Range Finder
VORTEX RAZOR HD 4000 Laser Range Finder By: Sal Palma
Earlier in 2019, Vortex Optics, one of the most highly regarded magnified optics manufacturer in the United States, announced an addition to its existing LRF line, the Razor HD 4000 laser range finder, and it has to be one of the most notable product announcements of the year. If Vortex Optics doesn’t ring a bell, you need to experience the company’s Razor line of rifle scopes, some of the best glass you can buy at any price. I’ve wanted to review one of their laser range finders for quite some time but never got around to doing that, so when they introduced the Razor HD 4000, I thought to myself, that’s the one. Along the way, I’ve reviewed a number of laser range finders, including the military grade equipment from Safran Vectronix and Newcon Optik. I also learned that consumers don’t understand laser ranging, so before I get to the
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Vortex Razor HD 4000, I want to touch on the many nuances of laser ranging. A laser range finder fires a pulse and measures the time it takes for the return. It operates in the infrared spectrum and can be detected using night vision equipment when looking straight at it. Military models are available that operate outside of the i.r. spectrum in order to avoid detection. The laser pulse also has a beam width that’s generally expressed in mils, 1 mil is equal to 0.05625° so a .1 mil beam width translates to 0.005625°. The laser pulse beam starts to diverge as soon as it leaves the rangefinder, so a narrow beam is highly desirable and common in high performance laser rangefinders like the Razor HD 4000. Although the LRF operates outside the visible light spectrum it’s also susceptible to atmospheric interference; for example, moisture in the air has a diffractive and attenuating effect. Atmospheric moisture is a disruptive phenomenon and functions like a bunch of little lenses floating in the air. Last but not least, range-finding over water is also a challenge. Ambient lighting will also influence a laser range finder’s performance. The ideal environment is a slightly overcast sky while the worst possible scenario is ranging directly into a bright sun. Next, there’s target reflectivity. A highly reflective target will return the laser pulse better than a target of low reflectivity; target materials will also impact laser ranging.
Copyright 2019, Twobirds Flying Publications, All Rights Reserved
Vortex Razor HD 4000 Laser Range Finder The ideal target is a highly reflective flat surface perpendicular to your line of sight. The angle at which the laser pulse strikes a target is called the incident angle and physics tells us that the angle of incidence is equal to the angle of reflection. The following illustration will clarify that concept.
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Those are a few idiosyncrasies of laser range finding and the reason why I chose “LRF Hell” to test drive the Razor HD 4000. If you want to put a laser range finder through the wringer, there’s nothing like a shipyard. Lazing Bambi pales in comparison to what you encounter in this environment and a shipyard is also much closer to what you would encounter in a theater of operation. Figure 1 LRF Hell
Note that at the illustrated angle of incident, the reflected laser pulse is not returning to its originating point, the LRF. In this case, you may not get a range. Therefore, the closer our line of sight is perpendicular to the target surface the better the reflection and the faster and more accurate the range will be.
Circular targets, like this oil storage tank, are challenging because there’s only one line of sight that will be perpendicular to its surface. The tank’s curvature ensures that some amount of your laser pulse will be reflected in a direction other than back to your rangefinder.
The Vortex Razor HD 4000 features 7X magnification with the best optical clarity of any rangefinder commercially available; surface textures, even rivets were easily resolved. Edge to edge sharpness and light transmission are superb. I was amazed and kept switching back and forth between a Leica LRF I brought along for comparison. To my eyes, the Vortex was handedly better. The HD 4000 has two modes of operation. The factory default, which Vortex calls HCD (Horizontal Component Distance), provides an angle compensated range.
Copyright 2019, Twobirds Flying Publications, All Rights Reserved
Vortex Razor HD 4000 Laser Range Finder When shooting angles, meaning inclination or declination, the shooter needs to determine the angle; then, calculate its cosine. He then multiplies the line of sight range by the cosine of the angle to determine the angle corrected distance. The HD 4000 makes that calculation for you in its default HCD mode.
The second is the LOS or line of sight mode. In LOS, the range finder displays the inclination or declination angle and the line of sight range. The shooter does the math work. The HD 4000 can also be set to range in yards or meters, the factory default is yards.
Operating the Razor HD 4000 is achieved using the MENU and MEASURE buttons. Vortex did more than just label them, they wanted a tactile indicator so the MENU button is smooth while the MEASURE button has four raised Braille like dots. I remember sitting there wondering why one would do that, but it was pretty cool and after all they are rifle scope guys.
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four, press the Measure button once then toggle through NORMAL FIRST, LAST and ELR by pressing the MENU button.
The targeting mode selected is shown in the upper left-hand side of the display. I’ll apologize right now for the image quality but the head on my digiscoping apparatus did not fit the eyepiece, so I had to jury-rig things. Nevertheless, you can easily see that I had LAST selected. All targeting methods are available in both HCD and LOS modes. You’ll want to use LAST when your desired target is obstructed by trees or brush. To scan the target area, select LAST using the MENU button then press and hold MEASURE while scanning. The HD 4000 will detect and lock in the furthest distance. It works extremely well; providing consistent results. I tested LAST in LRF Hell with impressive results.
The HD 4000 has four target modes NORMAL, FIRST, LAST and ELR. To move through these Copyright 2019, Twobirds Flying Publications, All Rights Reserved
Vortex Razor HD 4000 Laser Range Finder Take a look at the shoreline cover and the structure that’s barely visible behind it. The HD 4000 had no trouble ranging the structure, which is also not reflective, and as you can see from the photo, it did so with acceptable accuracy. The satellite image confirms the structure at 322 meters from my point of observation - impressive performance by the HD 4000.
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ship was docked, is designated P0024 2.7km (2700 meters) from my point of observation. FIRST is exactly opposite from LAST. You use this mode when your target is in front of a group of objects that are larger or more reflective than your target. To measure, after selecting FIRST targeting, depress the MEASURE button and hold while scanning the area of interest. The HD 4000 will lock in the closest range and display that. The LED display is adjustable for brightness from 1 to 5, one being the dimmest, an extremely nice feature especially when working in low light conditions. In bright and direct sunlight I was setting the display at 4 or 5.
I then tested the ELR (Extended Laser Range) mode.
In this trial, I wanted to get the range to the cruise ship. This was clearly a reflective target but take a look at the angle the target presents to the line of sight. The HD 4000 had no problem dealing with that. Again, I used a satellite image to confirm the range measurement. My point of observation is designated by the blue dot. The passenger terminal, where the
The HD 4000 is a light weight compact package. Vortex even provided a reversible belt clip and a very nice carrying case. I’m not a huge fan of rubber coatings, because they breakdown in
Copyright 2019, Twobirds Flying Publications, All Rights Reserved
Vortex Razor HD 4000 Laser Range Finder heat and humidity, so I liked Vortex’s implementation of a using a subdued texturing. Vortex’s Razor HD 4000 is a high quality, high performance ranging instrument. During my testing and evaluation, I ranged very difficult targets at a variety of ranges from 50 meters to 2,800 meters and all measurements were well within acceptable accuracy. Ranging was extremely fast except for my ELR test that took somewhat longer to display. All ranging was done over water and under very humid conditions in bright sunlight. As succinctly as I can say it, the Vortex Razor HD 4000 is an excellent offering from a small company who seems to continuously redefine excellence and performance. Whether by design or oversight, Vortex Optics left the long range shooting customer wanting. The long range precision shooter of 2019 integrates his or her platform with a weather meter and ballistic app. These apps run on smart devices and collect wind direction and speed, barometric pressure, relative humidity and other environmental data from a paired weather meter via Bluetooth, or Bluetooth LE (low energy). In order to compute a firing solution, the application also needs input from a rangefinder providing shooting angle, range and azimuth to the target.
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In the meantime, if you do not require Bluetooth integration, the Vortex Razor HD 4000 has my highest recommendation if for no other reason than its exceptional optical clarity. -SP
Manufacturer Specifications
Range Reflective (yards) 4000 Range Tree (yards) 2500 Range Deer (yards) 2200 Accuracy (≤ 199.9 yds.) .5 yds. Accuracy (200 - 1000 yds.) 1 yd. Accuracy (> 1000 yds.) 2 yds. Max Angle Reading + / - 70 degrees Magnification 7x Objective Lens Diameter 25 mm Linear Field of View 341.25 ft. @ 1,000 yds. Angular Field of View 6.5 degrees Eye Relief 16-19 mm Length 4.49 inches Width 1.34 inches Weight 9.9 oz. Product Manual (PDF) Download MSRP $729.99
In its present form, the Vortex Razor HD 4000 does not support Bluetooth connectivity to a weather meter or smart device. It also does not provide azimuth to a target. However, it wouldn’t surprise me to see a Shot Show announcement of a Vortex Razor HD 4000 B (for Bluetooth), mere speculation on my part at this point.
Copyright 2019, Twobirds Flying Publications, All Rights Reserved