Night Vision Round-Up Part 2

Rear-mounted NV add-ons are undeniably less sexy than the front-mounted ones used by the military! However, I prefer them because they take much less setting up, are incapable of causing a point-of-impact shift and will often do double duty as hand-held spotters. Just as importantly, they also let you retain your familiar sight picture, and with it all the optical sophistication and precision of your day scope.

Golden rule

A golden rule is that the objective-lens-toeyepiece length of a rear-mounted NV device should be as close as possible to the native eye-relief of whichever day scope you use (typically 90mm-105mm) as this minimises the need to adopt a different hold or head position with the NV fitted and makes for more comfortable and consistent shooting.

Rear-mounted devices that significantly exceed this distance will require the use of a slip-on butt extension or an adjustable stock. It follows that the most suitable scopes to use a rear-mounted add-on will have plenty of eye-relief. The lens coatings used can make a difference too, as some coatings reflect IR light, thereby giving the NV device less to work with. Parallax adjustment is also essential to ensure a perfectly-focussed image, since when mounted to the scope the primary function of the objective lens of the NV device is to focus the reticle rather than the scene. Further fine-tuning is typically available via a dioptre adjustment ring on the device’s eyepiece; another factor to consider when choosing a day scope for use with NV is magnification. 1.5X-6X is about perfect, since few devices are capable of giving a sufficiently bright and clear image above 6X.

Most NV brands offer a monocular that can be fitted to a fixed or folding day-scope adapter (DSA). These devices usually have a short-range –and thus largely useless- LED illuminator built in, but feature a threaded socket or short accessory rail for mounting something more effective.

Tubed

I won’t spend long here on tubed devices, but my own recommendation would be Cobra Optics’ Gen 2+ Titan (127mm), though Armasight’s Gen 2+ Sirius (157mm) and Starlight NV’s Gen 3 Archer (172mm) are also worth considering.

Digital

When it comes to digital add-ons, there are currently just two choices, the arrow from Starlight NV and the Atom from Nightmaster. Digital systems are unconstrained by the fixed dimensions of a conventional intensifier tube, giving a potential reduction in overall length.

The Arrow is made in the UK, has an agreeably-short critical length of 90mm, weighs 500g, is powered by two 3.7v rechargeable batteries, has a CDR of 300m with Starlight’s Dragonfly illuminator, and Starlight say it will provide a good image even at 12X magnification. It has no on-board recording or video out facility. The Arrow + Dragonfly combo costs £699.99 and is available exclusively from Starlight NV.

The Atom, meanwhile, is smaller and lighter, generally neater in design, and costs £499.96 on its own or £580.90 with a NM800-IR illuminator kit. It has a dioptre adjustment at the rear to focus the display, but uses a fixed-focus objective lens, so the reticle has to be focussed using the day scope’s dioptre ring. This isn’t hard to do, but does mean you have to set different day and night dioptre settings for your scope.

Two blue buttons on the R/H side of the Atom let you adjust the image brightness to maximise image quality and minimise eye strain - an advantage digital has over tubed NV- and a multi-socket on top serves to charge the internal battery, to connect Nightmaster’s WiFi module, or simply as a video port for external recording.

Nightmaster say the Atom will withstand the recoil from centrefire rifles, but the unit is principally designed for air-rifle and rimfire use out to a maximum of 140m.

TV screen with reticle

The most successful rear-mounted add-on design is of course the NiteSite. Its genius lies in throwing the aforementioned golden rule that rear-mounted NV shouldn’t alter the shooter’s position clean out of the window.

This meant that the designers no longer had to get their device to fit the eye-relief zone behind the scope and freed them to create a 3-part system in which a camera module is mounted to a tube that slides over the ocular bell of the day scope; a display/illumination module is mounted to the main tube of the day scope; and a power pack is mounted to the scope’s ocular bell or to the butt of the gun. The connecting cables weren’t pretty, but the screen, multi-LED illuminator and battery could be much bigger, offering greater visibility, reach and run-time.

The ball was now in the customer’s court: you could embrace the simplicity, versatility, performance and affordability of NiteSite’s design, and adjust your shooting style accordingly; or -in a market that did not as yet offer any digital alternatives- you could look the other way and buy a conventional tubed unit for well over twice the money. Guess what most people did?

From simple beginnings, the NiteSite has become a very sophisticated system, and a worldwide success. Their latest RTek models feature a removable MicroSD card for on-board recording, plus WiFi connectivity for remote viewing/recording on a smartphone or tablet. Meanwhile, controls for power, illumination, and reticle focus are located on the camera module, and there’s a brightnessadjustment dial on the LCD display.

The NiteSite range comprises three models of increasing capability: the Viper at £449, the Wolf at £639, and the Eagle at £849. In each case the RTek version costs an extra £300.

Front-mounted

The military uses front-mounted NV (a.k.a. ‘clip-on’) devices because the pronounced recoil of the weapons they mount them on requires plenty of eye-relief. Also, they can afford to buy the best kit available, and the targets they are trying to hit are big enough that minor point-of-impact shifts aren’t critical. Needless to say, the civilian market is a bit different. Nevertheless, frontmounted NV remains attractive, if expensive!

Tubed

Available tubed devices include ATN’s PS-28, which starts at around £2,530 for a Gen 2+ version; Armasight’s CO-MR, CO-LR and CO-X (£1,960, £2,880 and £2,075); and Cobra Optics’ Blade Pro and Orion Pro (£2,519.95 and £4,199.95). All these take an ‘in-line’ approach in which the add-on shares a common optical axis with the day scope.

Many can be mounted directly to the objective bell of your day scope, but it is preferable to use an over-barrel optics rail or railed hand-guard because this avoids any flexing of the day scope due to the weight of the NV device and ensures a consistent rotational orientation that minimises the risk of point-of-impact shift when the device is re-fitted.

Digital

If you want a digital clip-on device, then Pulsar’s Forward DFA75 (£1,229.95), a front-mounted device with a disconcertingly off-centre objective lens, is the only game in town. Recommended for day scopes in the 2X-7X range, the Forward DFA75 mounts to the objective bell via a cover ring adaptor of the appropriate size (sold separately). This adapter, which should remain securely attached to the day scope, permits rapid installation/removal of the device via a bayonet fitting.

To set up the device, you first calibrate it to your existing zero range, then to the reticle of the day scope, before zeroing it to the actual point of impact. This done, the DFA75 can be dismounted/re-mounted without re-zeroing. Finally, the higher sight line of the DFA75’s objective lens means you’ll have to compile a new ‘drop chart’ for the ranges you expect to shoot at with the DFA75 fitted.

Image quality is pretty good, thanks to a 640x480 OLED display and a highsensitivity Sony CCD. Brightness, contrast and sensitivity are all manually adjustable, or you can rely on the installed SumLight software to get the best image for the conditions. Digital needs more IR than tubed NV, so the DFA75 is equipped with a capable and covert 915nm laser illuminator with three power settings and a focusable beam, plus a side accessory rail for mounting a separate illuminator. A video-out port lets you connect the device to an external DVR or monitor, and you can also plug in an EPS3 or EPS5 external power pack. A wireless remote puts ON/ OFF and illumination control, plus SumLight image optimisation, at your fingertips.

Thermal

A rear-mounted thermal add-on wouldn’t work, because the lenses of the day scope block the heat signature, but a frontmounted device is now available in the shape of Pulsar’s Core FXD50. This is designed to do double duty as a monocular spotter, so comes with both a focusable eye-piece and a day-scope fitting. To mount the Core to a day scope you will also need a cover ring adaptor, as per the DFA75. A horizon function in the Core lets you square it to the reticle of your day scope, at which point you can lock off the adapter and leave it in place. Like the DFA75, the Core mounts to the adapter via a bayonet fitting with a sprung locking catch, but unlike the DFA75 it aligns directly with the optical axis of the day scope. There should be no point-of-impact shift with the Core fitted, but a software function lets you calibrate the device precisely, if needed.

The Core itself is a kind of pared-back Quantum XD50, with reduced dimensions (190mm x 65mm x 60 mm vs. 200mm x 86mm x 59mm), and with no external power socket or video-out port, but still with a 384x288 / 25μm sensor running at 50Hz, a 640x480 green OLED display, a base magnification of 2.8X with a digital 2X boost, and a CDR of 1,250m. Power comes from 2 x CR123A cells, and it’s worth buying a bulk pack because a set will only last you a couple of good outings. The Core costs a hefty £3,399.95, but its ability to convert any day scope into a thermal sight, as well as to function as a standalone monocular, makes it the most radical NV device to date and it can only be a matter of time before a 17μm XQ version comes along, hopefully with added ports!

ATN and Armasight also have frontmounted thermal devices in their inventories, but as yet these have made little impact on the hunting market in the UK.

Rangefinding for NV

Normal laser rangefinders are no good at night, because you can’t aim them accurately, so one of the greatest limitations on night shooting isn’t seeing your quarry, but working out how far away it is! The devices mentioned below set about solving this problem in different ways

The Pulsar Quantum XQ monocular assigns a standard height to 4 quarry species (hare/fox/boar/deer) and lets you measure the animal you are aiming at by scrolling two horizontal stadia together until they bracket it, at which point it will display the estimated range With practice you can achieve a fair degree of accuracy at practical ranges.

The ATN X-Sight uses a similar system, but here you point-and-click on the top edge of a target of known size and then do the same on the bottom edge. The sight responds by displaying the range and adjusting the reticle position accordingly! Accuracy is down to the user’s skill in taking the sightings.

The Pulsar Digisight LRF 970N uses a conventional laser rangefinder, with a range of 400m, integrated into the sight’s electronics. The result is that the laser is permanently aligned with the FoV by the architecture of the housing, the controls are centralised, and the output is instantly visible in the scope’s display. Since the rangefinder uses an IR laser you can see its “point-of-impact” in the NV, and so achieve greater precision by night than you can by day!

NiteSite have recently introduced their own a laser-rangefinding unit, with a range of 500m. To date it only has a mount to fit their display/illuminator module, but it is crying out for a regular scope or Picatinny bracket that would permit its use with all IR sights. In place of a normal viewfinder, a small LCD screen at the rear of the rangefinder displays the range and the angle of incline.

Underneath the screen are two rubberised buttons for activation and mode selection. It costs £299.

Contacts

Armasight: www.armasight.com (UK: Night Vision Gear UK)
ATN Corp: www.atncorp.com (UK: ATN EU) ATN EU: 0203 7446303; www.atneu.com
Cobra Optics (Thomas Jacks Ltd.)
Nightmaster: 01535 611688; www.nightmaster.co.uk
Night Vision Gear UK: 02830 263235; www.nightvisiongear.co.uk
Optix Co.: www.optixco.com (UK: Rovicom)
Rovicom Ltd: 01253 206221; www.optixnightvision.co.uk
Scott Country Ltd: 0556 503587; www.scottcountry.co.uk
Thomas Jacks Ltd: 01789 264100; www.thomasjacks.co.uk
Torrey Pines Logic: http://tplogic.com (UK: Scott Country Ltd.)
Yukon Optics: yukonopticsglobal.com (UK: Thomas Jacks Ltd.)
Pulsar: www.pulsar-nv.com (UK: Thomas Jacks Ltd.)
Wuhan Guide Infrared Co., Ltd.: http:// guideinfrared.com (UK: Thomas Jacks Ltd.)
Starlight NV: www.starlightnv.co.uk; 01942 884378
Nite Site: www.nitesite.com 01759 377235
General Starlight Company: www.gsci1.com [UK: Night Vision Gear UK]