Pulsar digisight LRF N870

Digital NV devices offer several inherent benefits: they’re day-safe, have tuneable displays for optimal performance in a variety of light conditions and physical environments, scrollable on-screen menus, image sharing/ recording, and so on.

The LRF N870 ticks all these boxes very well: it has two zeroing modes designed for ammunition economy and easy repeatability; the image can be tuned manually for brightness and contrast or you can activate the smart SumLight function which monitors the sensor and automatically optimises the Digisight’s output; its menus use easily understood icons and are accessed by a large wheel on the R/H side that uses an intuitive combination of click-stop rotation (scrolling) and a central push-button (confirmation); and a video-out port protected by a rubber cover provides connectivity to a recorder such as Yukon’s MPR or the Newton CVR640, both available via Thomas Jacks Ltd. and highly recommended for recording your sorties and successes.

In addition to foolproof menu options and controls on the LRF N870 Pulsar have squarely addressed two major factors that can limit the effectiveness of any night-vision shooting system: i.e. rangefinding and cant.

Rangefinding

It takes a very practised eye to assess range accurately, so most of us now use laser rangefinders (LRFs). By day, these are great, but most are scant use in the dark (images are too dim, reticles too bright), leaving us dependent on mere ‘educated guesswork’ or pre-prepared range cards (mine are on my phone).

The core aim of NV devices is to restore the capabilities that darkness takes away, yet most address this only in terms of imaging. Pulsar have taken a commendably broader view, restoring a crucial capability by integrating an LRF into their Digisight. No more guesstimating, just aim, blip the rubber button on sight (or the wireless remote), and read off the distance. There’s a scan mode too, so you can quickly take multiple readings to confirm a single point or range a series of points in succession to bracket unreflective spots. Moreover, the Digisight can see the ‘footprint’ of the LRF’s laser, so you can be sure you’re ranging the right spot. The N870’s LRF also has True Horizontal Distance (THD) and Angle of Elevation (AoE) functions, is accurate to ±1m, and is rated up to 400 metres. My furthest target pinged was 488 metres, so basically anything shootable is rangeable at the push of a button.

Cant

An anti-cant function also aids accuracy. By default, ballistic charts assume a sight line directly above the bore. If a rifle is canted (i.e. tilted to one side) when zeroed, or when used in the field, the trajectory of the projectile diverges from the ballistic prediction and a miss becomes more likely. The error increases with the degree of cant, the amount the projectile drops, and the distance between the optical centre and the bore (typically twice as great on NV-scoped rifles). Thus, if you are unknowingly canting the rifle you can do everything else right and still miss.

In the darkness we lose our normal horizontal reference points, but these are often misleading in any case, which is why precision shooters use anti-cant bubble levels. But these too are useless at night. Another victory for the powers of darkness… Again the LRF N870 has the solution. Activate the ‘level’ icon in the menu, and you’ll see a horizontal line on either side of the display accompanied by a chevron pointing up or down.

Just tilt the rifle as indicated. When the rifle is cant-free the indicators disappear. Put simply, this means you’re more likely to hit your target with an LRF N870 than with any other night sight.

Quick-Access

The LRF N870 has a quickaccess function button on the R/H side of the housing. The main menu lets you assign one of three functions to it: SumLight (ON/OFF), Reticle Colour (four variants), or Weapon (three presets). Also easy to access are the brightness, contrast and zoom adjustments. Just press the main control button once, twice or three times to select the one you want then turn it to adjust the value.

The LRF N870 also comes with a remote control. Lightweight and unobtrusive, it has three buttons (power ON/OFF, IR and LRF). A selfadhesive Velcro pad lets you mount it wherever you like, and the fast access it gives to the IR settings and LRF makes it a real asset in the field, though I’d happily swap the ON/OFF function for a picture-in-picture (PiP) function, as found on Pulsar’s Apex thermal sight.

Zeroing

The first step is to set your rifle up in a rest and shoot one round at a target. Then there are two options. Option 1: “Freeze Frame”. Find the ‘snowflake’ icon in the menu, centre the target (= point of aim = POA) in the reticle, and press the selector button. This takes a still image of the target and reticle, and superimposes a red ‘X’ that you centre on the point of impact (POI) by toggling vertical (Y) and horizontal (X) co-ordinates. This done, push the selector button again and the Digisight centres the reticle and image on this point. Option 2: “Live Zero”. This keeps the image active and requires the rifle to be kept pointed at the POA throughout but the process is otherwise the same.

Firing a second shot should confirm zero. For finer adjustment you can tweak the numerical co-ordinates of the cross hairs, as when adding or subtracting clicks on a conventional optic (N.B. If using a bolt-action rifle, ‘bore sight’ first by removing the bolt and sighting down the barrel to align it with the target, then entering zeroing mode and adjusting the cross onto the POA).

The major limitation when zeroing is that the Digisight’s image – bright, contrasty, wide-angled, and controllable though it is – is not especially sharp, whereas the reticle and zeroing overlays are quite bold and the 4.5x magnification gives only a relatively small-scale image of the target, making it tricky to get the reticle and the zeroing ‘X’ exactly centred on the POA and POI respectively.

You can’t use the digital zoom either as this is disabled in both zeroing modes. It is important therefore to use bold zeroing targets and select the reticle design (there are 13 to choose from!) that is most compatible with them. (You can select a different one to hunt with without affecting your zero.) As for the POI, this is best assessed using a conventional high-magnification optic.

Getting Physical

In addition to the Menu, QF, and LRF buttons already mentioned, there are two further manual controls: a power knob and a focusing knob. Unlike the side-parallax turrets found on day scopes, the latter is smaller and has click stops for more positive focus control. It can be easy to over-adjust at first, as despite the high-specification sensor and OLED display the image is never pin-sharp. Make no mistake, for digital NV, it’s very good indeed. Perhaps it’s just that the rest of the package is so capable that you find yourself seeking perfection everywhere! Note too that switching from ambient light to the 915nm wavelength of the on-board IR requires the image to be refocused accordingly.

Illumination

The power knob has five positions: OFF, ON, IR1, IR2 & IR3. Many on-board illuminators perform poorly, add bulk and drain batteries, but Thomas Jacks Ltd. have got Pulsar to equip the LRF N870 with a proper covert 915nm laser. This works out to an impressive range of around 225m. The laser does sap the batteries though. So I’d recommend buying an external battery pack to keep from running low on power.

You could buy an external laser instead, but as mounting one to the top accessory rail either partially blocks the LRF button or prevents the lens cover from being safely folded back over the top of the housing, a power pack seems the better choice.

If you do opt to add an external laser, choices include Pulsar IR X850 (LED) and L-808S (Laser) models. I’d recommend the former, as LED illuminators don’t require eye-safe filters and so give a cleaner beam. Like the L-808S, it has a built-in weaver mount, a rotating lens bezel to adjust the width of the beam (spot/flood), a dial on the top to vary its intensity, and runs on two AA batteries.

Power

Energy-saving modes that (A) automatically switch off the scope after 10 seconds if it is at a 70-degree vertical or 30-degree horizontal angle and (B) disable the video-out function mean the LRF N870 will give you a generous run time from 4x AA batteries – I got three three-hour outings on a single charge – provided you keep laser use to a minimum. With the laser on max, however, you can virtually watch the power drain away via the on-screen icon. Installing 4x AA cells in the battery compartment tucked away under the eyepiece extension is quite fiddly too… another reason to get an external battery pack.

Mounting

The LRF N870 is easy to mount too. It has a clamp that is compatible with most rail systems, a recoil block that is removable (and can be inverted to fit narrower Weaver or wider Picatinny rail slots), and bolts that can be precisely tightened with a torque wrench. It also reaches back 16cm so you don’t have to stretch your neck out to look through it.

Left-handed users don’t fare at all badly, despite the fact that on a L/H bolt-action the LRF binnacle will obstruct the bolt handle if you mount the sight all the way back, and that adding an external EPS3 powerpack on the L/H rail will block it completely. Why? Because an EPS3 will go on the top rail just fine, and because when shooting from the left shoulder having the major controls on the R/H side makes them more visible, and easy to operate with the ‘weak’ hand when using sticks, a bipod or a front bag.

At the time of writing I’ve (A) zeroed the scope wellenough to ring a steel fox-head target at 200 metres and 4.5x by day (nice, but very different from shooting at live quarry. See below) (B) detected and ranged a fox at 380 metres and (C) taken foxes at 72 metres and 110 metres, and rabbits out to 130 metres. Nevertheless, I passed up a shot at a fox at 200 metres, judging that ‘tolerance stacking’ in the sight picture, the zero and the operator tipped the odds against making a clean kill. More practice may make me revise that view, but the “If in doubt: DON’T SHOOT” rule will always apply.

Conclusion

I am hugely impressed by the Pulsar LRF N870 Digisight. No other night sight I have used offers so many practical and effective aids to observation and precision shooting during the hours of darkness (and in daylight too, if required). What’s more, The LRF N870 comes with a three-year warranty and the expert aftersales support of distributors Thomas Jacks Ltd.

PRICE: £1549.95
ACCESSORIES INCLUDED:
Wireless remote control, Weaver/ Picatinny Rail Mount, Soft carry case, lens cloth, short AV lead

OPTIONAL ACCESSORIES:
External Power Pack EPS3: £84.95,
Recording Device MPR: £179.95,
Laser illuminator L-808S: £109.95,
LED illuminator IR X850: £124.95,
Alternative Rail Mount: £49.95