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iGen Low Light Passive Performance

Night Vision Buyers Guide

      People have been fascinated by Night Vision technology ever since the Vampir NV Rifle Scope entered service in 1945. Things have progressed to the extent that several devices offer viable capability at a reasonable price. Unfortunately, no economical device will do everything. This buyers guide explains which device is best suited to each task, so you can purchase the appropriate product for your circumstances. I have selected devices to suit general purpose, hunting, home defense and tactical duty.

All Night Vision Image Intensifiers benefit from additional IR illumination but the ability to operate without it, is highly desirable. When most people use the term Night Vision, they are referring to passive technology that permits the operator to observe in a stealthy manor, without additional IR. Until recently, none of the affordable NVDs were viable passive devices. Day optics with high exit pupil, exceed commercial Gen 1 passive capability. Most Digital Night Vision Devices are equal to commercial Gen 1 with respect to passive performance.

Some Digital Night Vision monoculars had passive capability but did not fit any market niche. Retailing for $1000+ excluded them from the recreational sector. Inferior performance to Gen 3 NVDs eliminated them from the demanding tactical sector. The Digital iGen is unique in that it delivers Gen 2 levels of passive performance (min 1/4 moon) at a very attractive price point. The superior 12 degree field of view and passive capability make it ideal for hikers, hunters, bird watchers, astronomers and boaters. It is also useful to search and rescue, security personnel, patrol officers and private investigators.

The iGen is the only digital device that is manually optimized to suit the task and lighting conditions. Adjustments are controlled on-screen. Gain and Exposure are the main parameters. Gain will make objects stand out from their background. The image becomes 'snowy' or 'noisy' with high gain, making long distance objects harder to identify. Exposure can be considered shutter speed. Larger portions of light are processed when the shutter speed is reduced. When shutter speed is set below 10 Frames Per Second, the picture becomes jumpy with movement. Use high gain for land navigation and other close range, mobile tasks; use low shutter speed for static, long range observation.

igen Display Color Comparison

Display color is selected on-screen; choose from white, red; green or blue. Red fully preserves the eyes night adaptation but reveals less detail. White reveals the most detail but leaves the eye night blind; partial recovery takes ten minutes. Green is a compromise, offering good detail and recovering night adaptation in three minutes. Use red for intermittent observation such as land navigation or patrol; use white for continuous static observation. Some people develop headaches viewing the white display; it is possible to develop tolerance by brief exposure, gradually extending duration.

The iGen's 12 degree field of view and frame rate in extreme low light make it unsuitable for tactical duty. The 1 year warranty is on par with commercial grade Night Vision. Battery compartments are a wear area for power hungry Digital Night Vision. Upgrading the iGen with a metal, two piece, screw cap, battery compartment, would increase long term durability. The two piece cap could use a lock ring, similar to Vostock dive watches. I would also like to see an external power socket incorporated to enable continuous 8 hour operation, in conjunction with a Bolide AA battery pack. The unit would also benefit from a lanyard hole and picatinny accessory rail. On moonless nights, the monocular can be held in one hand complimented by a long range IR illuminator in the other hand. The Evolva IR illuminator employs beam focus to deliver extended range. It uses a non-standard battery and charger.

A 12 degree field of view is not optimal for night land navigation but the iGen is workable, if good fieldcraft is practiced. Use slow deliberate movement, have the head on a swivel, foot probe for ground obstacles and raise stride height to avoid tripping. Clear eye protection prevents injury from branches. Overall, the iGen currently offers the best balance of passive performance, versatility and value. It is programmed via a user friendly on-screen menu similar to BMW's iDrive. Currently, the next step up for general purpose NV is a Gen 3 monocular, which I discuss in the tactical NV section. However, high resolution FLIR monoculars and GEN 3 digital monoculars are in the pipeline.
iGen Monocular (USA)
Evolva IR Illuminator

Night Vision Hunting


Night hunting is legal in many countries with respect to vermin, varmints and predators. Check your local bylaws for restrictions on quarry, season, time, optics and other equipment. Range estimation, confirming a safe background and target identification are challenging under low light conditions. Lamping is the traditional method of night hunting. The equipment is bulky and heavy, making it more suited to ambush than stalking. Animals often become lamp shy, learning to avoid the light. Night Vision equipment offers more versatility and efficiency than a conventional lamping system. There are two basic approaches to hunting with Night Vision. The first is to use a NV monocular to spot but shoot with a conventional day optic. The other method is to spot and shoot with a Night Vision Rifle Scope (NVRS).

The first hunting configuration is robust, cost effective and not dedicated to exclusive night operation. Use an iGen monocular with the non-dominant eye to spot and stalk inside 100 yards. Use your night adapted dominant eye to sight with a day rifle scope. The human eye adapts to low light but resolves a monochrome image with limited detail. Cone cells in the retina are responsible for resolving detail, color and movement but don't adapt well to low light. Rod cells produce a pigment which boosts sensitivity to low light levels. It is neutralized by exposure to white light, preventing over sensitivity to daylight. Optical magnification compensates for the eye's reduced detail under night adaptation.

SS6X42MQ Reticle

Prior to the arrival of illuminated reticles, the heavy posts of German #1 and #4 reticles were favored for night shooting. The SS6X42MQ scope incorporates an inverted #4 reticle into a precision MRAD reticle. Its 6x magnification and 7mm exit pupil make it suitable for day and night shooting. Zero on the top post, similar to the British SUIT scope. The MRAD reticle below may be used as a ballistic plex. Rod cells are most dense in the retina's periphery. Utilize their sensitivity by offsetting central vision to the left of the reticle. This technique provides more image detail for a few seconds. Most illuminated reticles are developed for legal game hunting at dawn and dusk. Subsequently, they are excessively bright for moonlight conditions, washing the image out.

The eye's pupil dilates to 7 mm under night adaptation, enabling more light to reach the retina. Conventional rifle scopes capable of producing a 7 mm exit pupil at 6 x magnification, produce optimal images under modest moonlight. An optics's exit pupil is calculated by dividing the objective lens diameter by the current magnification setting; 6x requires a 42 mm objective. Exit pupils broader than 7 mm won't appear any brighter, as the extra light fails to pass through the eye's pupil. Larger objectives permit more magnification and consequently more detail but objectives larger than 50 mm become impractical due to weight and bulk considerations. Premium glass delivers notably superior contrast and resolution in extreme low light. Scout scopes and reflex sights can't match the images produced by conventional rifle scopes under these lighting conditions.

Hunting Illuminator

Visible illuminators give the shooter more options than waiting for the moon to come out. Get lined up by bouncing light from the ground onto the target, then raise the weapon to make the shot. The Kill Light is a compact, powerful flashlight that uses a colored LED for superior range. Filtered white light can cut light output by as much as 50%. The unit can mount to a scope or barrel. Beams are colored to reduce spook rather than preserve night adaptation. Maximum engagement range of the visible red illuminator is 150 yards, detection by eye shine can range out to 250 yards.

Spotting and shooting with Night Vision equipment is stealthier than employing visible illumination. The animal will not be alerted until the shot is made. Infra Red light is difficult to detect with the naked eye. All other factors being equal, a dedicated Night Vision Rifle Scope (NVRS) will provide more range than a monocular. Low magnification monoculars make the best spotters. A 4x NVRS delivers more detail and accuracy at the expense of field of view. An NVRS will dedicate the host weapon to night only operation. My recommended entry level NVRS is the ATN MK390. The image clarity is superior to competitive products and will support predator hunting with sufficient IR illumination. The controls are straightforward and easy to locate under darkness. The 12 degree field of view will enable spotting and shooting through the scope but sustained observation will require the support of a bipod or shooting sticks; the MK390 is bulky and heavy.
Super Sniper 6x42
Kill Light


The MK390 has 4x magnification, good clarity and very little of the fish eye distortion typically experienced with Gen 1 NV. Center image resolution of 40 lp/mm is perfectly usable but decreases on 30% of the peripheral sight picture. The image is blurred but remains aligned. It's extremely difficult to take representative photographs of Image Intensifier Tubes; using IR illumination washes out the photo camera but the naked eye sees greater detail. Most promotional Gen 1 images are doctored daylight photos. The photo below uses urban street lighting to represent MK390 clarity with strong IR illumination. Magnification of 4x is recommended for identifying animals in excess of 50 yards. The size of the animal will impact effective range, in terms of identification and ethical shot placement.

Commercial Gen 1 NVRS have more in common with the Gen 0 Vampir than true military Gen 1 NVRS of the Vietnam era. They should be considered active systems, heavily dependent on Infra Red illumination. This doesn't present a problem for night hunting in open ground. Obscurants such as snow, hail, rain, mist, fog and dust will reflect IR illumination but won't render the NVRS entirely ineffective. The MK390 comes with a detachable IR illuminator that is adjustable for alignment, focus and IR output. It enables a viewing range of 75 yards with no moonlight, to 150 yards in full moonlight.

MK390 Image

The adjustable output prevents wash out at close range. IR laser illuminators offer the most range and stealth. Unlike 805 nm LED illuminators, there is almost no visible red glow emitted. Luna optics offer laser IR illuminators to the general public. However, most night hunters are better served with a long range LED IR Illuminator that doubles the range of the standard ATN unit. Quality LED units have superior durability, simplicity, ease of use, value and safety than laser illuminators, which are more suited to low light tactical operations.

The MK390 uses a red projected reticle, which is brightness adjustable. It is perfectly calibrated for low light conditions but is not visible in daylight conditions. The scope must be zeroed at dusk. Solid cheek weld and consistent eye relief are essential to achieving accuracy with the NVRS. A cheek piece will be necessary for most rifles. The MK390's mount has a forward bias, which is not ideal for the AR-15 pattern. ATN offers an optional long rail adapter for optimal eye relief on this platform. Rifles with dovetails will need a weaver adapter.

The only other issues are the bulk and weight of the MK390 and fragility of Image Intensifier Tubes in general. Make sure to activate the unit once a month or the internals may perish. Rechargeable batteries are subject to voltage spikes and will fry tube based NV like the MK390. The recoil from 12 gauge shotguns, muzzlebraked magnums, crossbows and spring powered airguns will destroy an NVRS. The scope comes with a 2 year warranty but you may expect many years of service if you baby it. The MK390 doesn't have the prestige of Gen 3 or Flir equipment but has a good service record with British airgun hunters and American predator hunters.

The next practical advance for night hunting is a Gen 3 Night Vision Rifle Scope. Gen 2 is neither fish nor fowl; while the image is flat from edge to edge, the center resolution can be as low as 24 lp/mm with some of the cheaper units. That is almost half the clarity of the MK390 and precludes any long range target identification. Gen 2 doesn't have the light amplification to be considered a passive device. It works well in urban and suburban areas but medium range rural hunting will require a powerful IR illuminator. A 6x magnification Gen 3 NVRS is only necessary when engaging beyond 150 yards.
Evolva IR Illuminator

Low Light Self Defence

Home Defense

Home defense begins with secure doors and windows, particularly in the bedroom. This gives enough time to respond to aggressive nocturnal intruders. Night Vision equipment has little value in home defense or self defense scenarios. A 1 x magnification NV monocular has a quarter of the the naked eye's field of view. Higher magnification NV devices have even less. This restricted view is most pronounced at close range, slowing threat detection and discrimination. A tactical flashlight will illuminate the entire field of view at close range, supporting prompt confirmation of the target and its background.

Visible laser aimers are often marketed as infallible aiming solutions. In reality, the small dot is relatively slow to acquire in reactive circumstances. Once acquired, the laser's dot can be targeted quickly. Visible laser aimers primarily support unorthodox shooting techniques that preclude conventional eye to sight alignment. For example, aiming a handgun with a ballistic shield, aiming a rifle with a gas mask or using the high tuck position, to shoot a rifle single handed, due to injury. Red lasers (5 mw) have a bright light range of 10 yards. Green lasers (5 mw) have a bright light range of 25 yards. Cheap visible lasers will not withstand rifle recoil or retain zero. At room distance, the hot spot of a weapon light can substitute for a laser aimer.

Tritium Sights

Tritium sights perpetually glow by housing a vile of a gas, which is excited by an integral radioactive element. They have a useful life of approximately 10 years. They are superfluous for home defense. If ambient lighting conditions are so poor as to prohibit standard sights from being acquired, then target discrimination with the naked eye is impossible. Employing a light source to identify the threat will also effectively illuminate standard sights, particularly those sporting a white dot or 'skunk stripe'. The original concept for Tritium sights was that soldiers would place the glowing post on muzzle flashes from enemy lines. Given the liquid nature of modern combat, this practice is no longer feasible. Tritium sights and visible lasers may act as target indicators telegraphing the user's position.

Visible light also also draws fire; prevent telegraphing position by avoiding back light. Discriminate threats through momentary light activation. White light provides faster image resolution than colored light at the expense of natural dark adaptation. Some natural night vision will be retained by closing the non-dominant eye when discharging white light. If using a weapon mounted light, bounce the beam off a wall or floor, rather than pointing the weapon directly at the subject. Scrutinize the targets face and collapse to their hands to scan for weapons. Defending a position is tactically and legally advantageous. Rear security makes clearing a house a minimum two person exercise.

Shotgun Light

Tactical flashlights must be exceptionally durable, reliable and simple to operate (fixed focus, single output mode). They fall into two basic categories, weapon mounted and handheld. Long guns require two handed operation, necessitating the light to be affixed. Despite their report, recoil and bulk, pump action shotguns are the preferred home defense long guns, because of their ease of use. A novice will be effective after a 100 cartridge training session. The high tuck technique is effective to 7 yards and eliminates recoil transmission to the body. Bend at the waist. The knees will sympathetically bend. Tuck the stock high and tight into the armpit, letting the buttpad protrude out the back, cant the head to align the master eye over the bore and square up to the target. Choate's rugged top folding buttstock, particularly suits the high tuck technique, as its low comb brings the bore closer to eye level. Loctite the mounting bolt after function testing.

The Remington 870 is prolific, politically correct, economical, effective, durable and simple to maintain. However, its reciprocating forearm makes light attachment problematic. Pictured above, an MOE forend, SMC mount and Surefire flashlight is the preferred method. It's ergonomic, simplistic, durable and reliable. The 6PX Tactical tail cap locks out constant activation, which requires a deliberate twist. The Surefire 6P handheld flashlight has earned a legendary reputation in military, law enforcement and self defense circles. It has proven durable, reliable and simple to use. The latest 6PX matches the high output of contemporary lights but retains the durability and simple operation of the original model.

Contemporary service pistols usually incorporate rails into their dust covers to accommodate compact weapon lights. However, many handgun designs don't have this feature. A popular solution is to adopt the Harries technique. The support hand holds the tactical flashlight in a reverse or "ice pick" grip. The gun arm is at full extension. The wrists nest together and the backs of the hands are firmly pressed together to create stabilizing isometric tension. The flashlight's tail cap switch is operated by the support hand's thumb. The inverted Harries can be used from a compressed ready position, which is less fatiguing. The bottom of the support wrist is placed on top of the gun arm's forearm, several inches away from the gun arm's wrist. Somewhat like a Kerambit, the switchback ring provides greater retention in flashlight deployment, weapon malfunction clearance and reloads. Its optional activation technique, may not hold up under stress or compliment revolvers. Large models fit the 6PX. Remove carbon fouling from a flashlight lens with simple green or a pencil eraser.
MOE 870 Forend (USA)
SMC Mount (USA)
870 Top Folding Stock (USA)
6PX Tactical Flashlight (USA)
SwitchBack Ring (USA)
Simple Green

Gen 3


As explained above, weapon mounted white lights are better suited to searching vehicles and buildings. An opaque flip cap prevents negligent discharges of white light in open ground. Autogating monoculars automatically reduce light amplification when exposed to bright white light and are effectively compatible with visible flashlights. The fundamental purpose of tactical Night Vision is to detect and engage threats before they detect you. Owning the night begins with a high performance flash suppressor. 3D camo such as burlap weapon wrap, burlap head dress, sniper veils and leafy hoods counteract the washout of disruptive patterns under the monochrome display. Excluding dedicated NV Rifle Scopes, tactical Night Vision Devices are used in concert with other aiming equipment. They are not a stand alone solution.

Iron sights have limited compatibility with Night Vision Devices. NVDs have restricted depth of focus, preventing direct sighting through irons. Either the target or sight will be out of focus. Technically, the Bindon Aiming Concept (BAC) of helmet mounting an NV monocular over the non-dominant eye and sighting with the dominant eye is possible. Tritium sight inserts provide the low light aiming reference and the brain superimposes the two images. This works reasonably well with handguns. However, monocular image offset prohibits any practical application of BAC with long guns. Typically, shooting with Night Vision is executed by helmet mount and IR laser aimer or weapon mount and compatible optic.

NV Helmet

Helmet mount offers the ability to scan independently of weapon orientation, providing a broader view of the environment. The cheaper "skull crusher" head mounts place all of the weight on the forehead and are too painful for prolonged wear. Pro-Tec Bravo helmets are affordable and designed to support tactical night vision. Holes are pre-drilled to accept the latest shroud plates. Mil-Spec mounts consist of three components. Base plates strap onto helmets. Spring-loaded flip up 'Rhino' mounts lock into the plate. 'J-Arms' connect to the monocular via its tripod socket. The J-Arm slides onto the Rhino's dual rails and is secured by a spring latch. The J-Arm adjusts for eye relief by depressing the latch and sliding along the Rhino's ratcheted rail. The J-Arm also articulates like a binocular hinge to adjust for eye position, movement is friction locked by a knurled thumbscrew.

The three main issues with helmet mounted night vision are weight, wobble and focus. The PVS-14, Rhino and J-arm are constructed from aluminum and weigh enough to induce neck pain as muscles fatigue from resisting their leverage. The preferred solution is to attach a counterweight to the rear of the helmet. All three components have intrinsic wobble which can't be improvised out. The friction locked J-Arm is easily knocked out of position, effectively blinding the operator. Pictured above, Norotos have released their improved INVG system consisting of bolt on universal shroud, redesigned mount, resembling a scope ring on a triangular spigot and lastly, a rigid monocular dovetail which clips into the 'ring'. All articulation is through the mount, which is extremely stable and secure.

The helmet mounted PVS-14 is worn over the non-dominant eye, freeing the dominant eye for instantaneous transition to day optic and white light. Focus and gain should be set after helmet straps are tightened and monocular fit adjusted. Adjust the objective first then eye diopter. Set the focus on an object past 15 ft. Objects inside 15 ft will become progressively blurred the closer the are. Scanning compensates by maximizing the naked eye's sensitive peripheral vision. Use the least eye diopter to minimize eye strain. Turn it anti-clockwise until the image is blurred then clockwise until sharply focused. Monocular focus should remain fixed once set, attaching the pin holed lens cover brings maps into focus. Gain is adjusted to prevent overriding the naked eye's night adapted image. Select a mid range light source and adjust the gain until a contiguous image of bright center and adapted periphery is presented.

IR laser aimers are undetectable to the naked eye and the only practical means of shooting long guns with helmet mounted night vision. The IR laser dot is easy to acquire through an NVD and provides the fastest means of engagement. Military variants project out to 500 yards but a fixed zero limits effective range to 300 yards. It's possible to accurately shoot from unconventional positions but shouldering the weapon is preferred, which supports rapid transition to day optics and white light.

Military grade IR lasers are prohibited from public sale but Steiner Optics now offer their D-BAL IR laser aimer to civilians. This reduced power, class 1 variant is eye safe and has a projection range of 400 yards. Unless mounted directly over/under the bore, a laser beam's windage should run parallel to the line of bore, rather than intersecting it at a specific range. Wind drift not withstanding, this ensures a constant POI offset rather than the confusing POI shift experienced with an intersecting zero.

Weapon Mount

The prevalence of optics on carbines has relegated iron sights to back up duty. Optics keep both sight and target in focus, increasing hit probability in real world conditions of movement. The only reasons to weapon mount night vision monoculars are the economy of less equipment or when a complete absence of IR signature is desired. There are four common types of optics compatible with weapon mounted NVDs, ACOGs, EO Tech holographic sights, Aimpoint reflex sights and low power variable rifle scopes. The ACOG is the least suited for tactical low light employment. The reticle isn't visible until the eye becomes night adapted. The projected reticles of EO Techs and Aimpoints are practically parallax free, which means a cheek weld isn't required for accurate shot placement. This aids reflexive shooting and supports unconventional positions.

Projected reticles are particularly compatible with NVD's limited depth of focus. Infinite eye relief supports forward mounting, eliminating the need to align eye to eye piece, accelerating acquisition. Forward mounting a reflex sight assists weapon mounting of a monocular, effectively offering an improvised NV Rifle Scope. Tactical variants of Aimpoints have a specific low illumination mode to support this. Current PVS-14 weapon mounts interface behind the objective ring rather than the tripod socket. Helmet adapters and weapon mounts remain on the monocular, supporting rapid reconfiguration. The La Rue PVS-14 w mount is compatible with J-Arm and INVG helmet mounts.

Aimpoint + PVS-14

UNS devices were developed for sniper rifles and are too bulky for carbines. They mount in front of the rifle scope, on a free floating railed forearm, monolithic receiver or special adapter mount such as Badger Ordnance's unit for the popular AICS rifle stock. PVS-22's and other UNS devices may be used as hand held monoculars but cannot be helmet mounted. These devices provide an image but no integral aiming reference. Unlike dedicated NV Rifle Scopes, one UNS device can support multiple long guns, hence the designation of Universal Night Sight.

Currently two NV tubes are viable for tactical duty, the Gen 2+ DEP Supergen and the ITT Gen 3 OMNI IV. True Gen 2+ devices such as the European DEP Supergen are often marketed as 'Gen 2+ SHP' because surplus Gen 2 NVDs were already being promoted as Gen 2+ devices. Many soldiers preferred to use day optics than the blurry Gen 2 goggles of the 1980's. DEP Supergens have significantly better resolution and light amplification to that technology. Gen 3 NVDs provide a detection advantage to DEP Supergens in a limited number of circumstances, basically moonless rural conditions. Gen 3's autogating is arguably more tactically advantageous than its superior light sensitivity. Most DEP tubes are currently not equipped with autogating.

If you are purchasing a tactical Gen 3 OMNI IV NVD, make it an ITT factory built, Night Enforcer PVS-14. This has the latest technology of Pinnacle tube and autogated power supply. Pinnacle gives a brighter image and autogating compensates for bright white light without shutting down the device. The unit remains functional in the critical operation phase of transitioning from stealthy to bright and noisy. Please note that autogating does not protect NVDs from daylight exposure.

DEP Supergens are 70% of the cost of an ITT Night Enforcer but offers half the lifespan, so it is really worth stumping up the extra cash, if possible. Thermal Imaging Devices offer improved detection but don't make Gen 3 NVDs obsolete. Gen 3 is still required to identify that detection. Thermal Imaging devices resolve heat differentials into an image. Objects typically appear as a silhouette with limited definition. The only downsides to purchasing an ITT PVS-14 are the initial cash outlay and the inherent fragility of all Image Intensifier Tubes. The difficulty of trading it on is mitigated by the 5 year warranty on the tube and 3 year warranty on system components.
Bravo Helmet (USA)
INVG Helmet Mount (USA)
D-BAL IR Laser Aimer (USA)
PVS-14 Weapon Mount (USA)
Aimpoint M4

Questions & Feedback.

I hope you found this guide useful. If you have any questions or feedback, feel free to contact me through the welcome page.

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Ian ST John.

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