WANT NV? READ THIS A Buyers Guide to NVGs (Night Vision)

[BenG]

As nobody has addressed this and a bunch of people waste their money on gen 1 every summer season (including myself once upon a time) I have created this guide to help one choose a night vision device that will satisfy!

This guide is broken into a several major parts:

1) Terminology and tech
2) Generation Identification
3) importing
4) what to look for
5) Good Brands and devices
6) top end unit comparison

PART 1

IIT, I^2 = image intensifier Tube
NOD = night optical device
NVG = night vision goggle
AG = auto gate
MPC = micro channel plate
noise = in a NVG noise is similar to the static on your TV, as a NOD starts running out of light to amplify the image will start to get noisy and become staticy looking
S/R = signal to noise ratio the higher the S/R the lower the light level that can be reached before noise becomes an issue
lp/mm = line pairs per milimeter, the resolution of the night vision
gain = the amount of light amplication a NOD can do
FOM = figure of merit (calculated with (Lp/mm)*S/R = FOM) 1500 or less is exportable from the USA, gen 3 of any FOM is not premitted to export from the USA, ITAR and FOM is not an issue when importing from most of Europe

FOV = field of view

How does night vision work?

Night vision works by using three major components to focus and amplify existing light. The objective lens focuses light onto the IIT, the IIT amplifies the light and the eye piece focuses the output onto your eye. IITs work in various ways depending on the generation but the gist is photons enter the objective lens and strike the photocathode in the IIT, the photocathode absorbs the photon and releases a storm of electrons in the same pattern. this storm of electrons may or may not pass through a MPC depending on the generation of the unit which releases even more electrons, these electrons then strike a phosphorus screen that absorbs the electrons and releases photons that are then focused onto your eye via the eye piece.

Other functions in a night vision device include bright light cut off which will shut the device off if exposed to to bright of a light, auto gating (gen 3 and XR5 tubes only), auto gate is fitted to the power supply of high end night vision and rapidly turns the unit on and off when exposed to bright light, like the shutter on a camera and allows the unit to function at a very high capacity when exposed to a bright light (like a flashlight). Automatic brightness control is fitted to most gen 2 units and some gen 3 units (in the absence of manual gain), Automatic brightness control (ABC) varies the gain of the NOD depending on light conditions so that you never have to much gain and blind yourself, and it will also increase the gain if light conditions deteriorate. Manuel gain is fitted to high end gen 2 and gen 3, it allows the user to control their gain by hand, and allows for precise control over ABC, manuel gain tubes are ALWAYS fitted with autogate.

Photocathode differentiation:

there are 2 types of photocathode, alkaline which is fitted to gen 1 and gen 2 and gallium which is fitted to gen 3. the photocathode is important because it determines which kind of light wavelengths the unit is best able to amplify. the Alkaline in gen 1 and 2 is most sensitive to blue and green light and that is why gen 1 and 2 function best with moonlight because they require visible light to see (to clarify, if with your naked eye you cant at least see your hand in front of your face gen 1 and 2 cant see either). the Gallium cathode in gen 3 is most sensitive to IR light in the low 900nm, and this invisible light is what is most available at night and is why gen 3 can seem to find light even in the pitch black.

photocathode sensitivity: (percents indicate what portion of light the night visions gain is using to produce the image, these percentages are not perfectly accurate and are only approximations)

gen 1 = 90% 400-700nm 10% 700-830nm (after 830nm gen 1 can not detect IR light)

gen 2 = 65% 400-700nm 35% 700-900nm

gen 3 = 1% 400-500nm 9% 500-700nm 90% 800-980nm (peaking at 930nm)

PART 2

Generation 1: Do not buy gen 1, it SUCKS.

Gen 1 night vision consists of an objective lens, an IIT fitted with a alkaline photocathod, and a eye peice. Typical gain range of gen 1 is 200 to 900, resolution is 10lp/mm to 40lp/mm, and gen 1 units have infinite S/R (no noise in any condition). Images are blurry and fish bowled its very hard to indentify even trees through a gen 1 unit. Gen 1 units require at least a half moon with clear skies to produce an image. typical price is 150-900$ and are not worth a single penny, if your going the gen 1 route spend your money on a nice surefire.

Generation 2:

gen 2 night vision consists of the same components and photocathod as gen 1 but features the additions of the MPC which increases the gain many thousands of times, higher quality materials also increase resolution. Gen 2 units are susceptible to noise and lower end units with S/Rs lower then 10 are often more unusable then gen 1 as the noise makes the unit impossible to see through, typical S/R ranges from 5-20 the XR5 can reach 28 S/R. The US state department considers 4000 gain to be the minimum gain to be tactically useful (from personal experience I would recommend nothing short of 15 000) typical gain produced from a gen 2 is 5000 (extreme low end, DO NOT BUY) to 50 000 (XR5). Resolution from gen 2 can range from 20lp/mm to 50 lp/mm and the XR5 can reach 74 lp/mm, however XR5s often cost as much or more then gen 3. gen 2 does not have fish bowl but some image distortion in the edge of the FOV can be expected.

Generation 3: (note for the purpose of this article I am ignoring omni 1-3 as they are not available for surplus and would be a waste of money)

gen 3 is the current state of the art NOD. Gen 3 uses all the same components as gen 2 including the MPC but replaces the alkaline photocathode with a gallium one that is more sensitive to IR light, produces higher resolution and less noise. typical S/R of gen 3 is 15-30, typical resolution is 64lp/mm and gain ranges from 40 000-70 000. Gen 3 produces bright high quality images, and function very well in low light with or without moonlight.

Generation 4:

gen 4 is the same as gen 3 but features the removal of the ion barrier (protects the photocathode from high energy photons) and the removal of the ion barrier limits tube life by a factor of 10 although some of the newer ones last much longer this makes them economically unfeasible. gen 4 can reach a gain of up to 110 000.

Part 3

It is not illegal to import any night vision device into Canada, however it is illegal to export a night vision device with a figure of merit greater then 1500 from the USA, or any gen 3 night vision device from the USA. It is very hard to get a US retailer to ship even less then 1500 FOM tubes to Canada as the penalty for exporting ITAR complaint items (night vision) is very high, therefore it is recommended to look in Canada or in Europe where such regulations do not apply.

Part 4

When buying a night vision unit your first stop should always be the tube data sheet*. you should look for the following:

a S/R greater then 15
a lp/mm greater than 40
you should verify that it is not a white phosphor tube (night vision is purpose built with a green phosphor because the human eye can differentiate the most shades of green) HOWEVER this comes down to personal preference, if you like white phosphor, for whatever reason, go that route.
if possible you should make sure the gain is at least 15 000
eye relief at least 15mm (20mm ideal)
a FOV of at least 30°, 40° is the best.
you should make sure your unit is compatible with j-arms if it is a monocular and dove or rhino compatible if it is a duel tube.

*it should be noted that contract tubes (typically will be advertised as "omni <insert roman numerals/number here> ex: pvs-14 omni 4/ pvs-14 omni IV) do not have data sheets instead the different contracts (omni's) had to meet specific specifications, each batch of a specific omni run may or may not have had a different requirment, the following chart can serve as a baseline or average reference for each contract, but your specific tube may be above or slightly below this outline.

Notes about contract tubes:
-omni I, II, III tubes are hard if not impossible to find
-it should be noted that omni VII and later tubes almost always come with autogating due to the fragility of the tube, which is both more fragile in its potential to be harmed by bright lights (although this is completely negated with autogating), and its physical resistance to shock (ex: recoil, being dropped), however these tubes produce greatly enhanced images.

Contract (omni) tube spec sheet reference:
http://www.ar15.com/forums/t_6_18/31...fferences.html

Part 5

Night Optics D300 SHP 1800-2300$ S/R 19+ Lp/mm 45+ gain 20 000 - 35 000 (gen 2 with XD-4 tube)
GSCI GS-14 (made in canada) http://www.nvoptics.com/products/gs-...monocular.html

any tube from photonis, specifically the XD-4 or the XR5

a an/pvs system with a omni 4 or later tube

part 6

the best tubes that I can possibly think of are the US gen 3 Pinnacle tubes and the photonis XR5. Both of these units are auto gated and can be bought with either ABC or Manuel gain. The XR5 is a state of the art gen 2 tube and produces the highest resolution available on any unit. The Pinnacle is a gen 3 unit and has the highest gain of any filmed tube. Both units are excellent choices, the XR5 has an advantage in resolution (S/R of 25-28, lp/mm of 74) where as the pinnacle will beat the XR5 in gain by a substantial 30 000 and has a spectrum advantage, but looses in S/R (25-30) and resolution (64-72). Ultimately because airsoft games are usually played at night with some moon the XR5 can be an attractive choice as its better resolution will come in to play, but in the trees and on nights with no moon the pinnacle will out preform the XR5 by a substantial margin.

[BenG]

Alrighty Ive got my NOD how do I mount it?

part 1 arms and weopon mounts
part 2 dovetail vs rhino
part 3 monocular vs goggle
part 4 counter weights
part 5 aiming
part 6 eye pro

part 1

There are several different arms available to hang your NV from your face and just as many to stick them behind your favorite optics. The most common mount is the USGI rhino arm from Norotos, its what I use, its cheap and gets the job done but the fine points of ajustment are for lack of a better word crude and if you happen to have a head shape that doesnt work with them it sucks to suck. Wilcox and norotos both make many excellent arms, the Norotos INVG mount is the best for monoculars and has many different low profile stow modes. Wilcox makes the LG-34 mount which is arguable the best mount of all. it has good ajustment and locks into place and has a low profile stowing position. Both the LG-34 and INVG can be had for about 600$ so they are not cheap investments. Things to look for in an arm: low profile stowing, firm ajustment, preferably with locking, and good QC that fits into your shroud perfectly. Ill be honest and say I dont know that much about weapon mounting however if I were to go that route I think aimpoint makes one that fits to the front of monoculars so you can leave your J-arm attached and quickly go from weapon to head mount.

part 2

Rhino or the horn mount is the standard and cheapest style of mount, its main drawback is its bulkyness and often poor fit, rhino style mounts like to wobble alot. Dovetail is much much lower profile, doesnt wobble as much and fits into the higher end arms like the INVG and LG-34. Im not going to cover anvis mounts as if your buying anvis you hopefully know what your getting into.

part 3

Monoculars and much more versatile then goggles and allow you to differentiate between visible and IR light. Goggles either bino or cyclopes style give more imersive experiances and esspecially with binos more depth preception and field of view. Personally, when I use a monocular and have it over my non dominant eye I feel sick, and my team mate feels sick after using his on either eye for a long period of time, however many many people do not have problems with them. Monoculars require the use of a J-arm either in horn or dove style to properly cant the monocular left or right to your eye. Goggles just have either a horn or a dovetail mounted in the center of them.

part 4

You will HATE your NV unless you have a counter weight. pouches are cheap I think i paid like 9$ for mine, and you can use pretty much anything to balance out the weight of your NOD, I use batteries or steel bars, but Ive had friends stick a can of beer in their pouch, and another team mate robbed the spare wheel lock nuts off his buddies truck for the duration of the night, even a big stick would work if your in a bind.

part 5

Aiming with gen 2 night vision requires the use of a laser, class 1 IR is the best because gen 1 cant pick up class 1 and with IR your opponents without NV wont be able to see it, further more class 1 laser are required for saftey to be used with NV as the IR beam wont trigger a blink reflex, (thundercactus is capable of modding G&P dbals to have the same output as a class 1 laser if your in a bind for one although his modded units are not accepted at all games), further more if you use anything more powerful then a class 1 laser the splash from the beam will trigger your ABC and/or auto gate depending on how close you are reducing how much you can see., which means that its in everyones best interest if you use a class 1 laser. Some high end optics have NV modes which allow you to use them to aim with your NV just like you would during the day and I reqomend these over lasers as they dont give your position away to other NV users.

part 6

Ill start this by saying your NV is NOT a substitute for proper eye pro and you MUST wear eye pro in conjunction with your NOD. As a general rule the closer you can get the NVD to your eye the better, even PVS-14s suffer when they are not super close to your eye, it is possible to use full seal glasses, paintball masks, etc but the amount of the NODs image you can make use of will suffer. Smith Optics AEGIS glasses work well with NODs, so do Oakley tombstones and M-frames

[BenG]

reserve 2

[c3sk]

Good writeup BenG.

Few things:

I think you mean IIT instead of ITT (ITT would be the nightvision company now known as Exelis/Harris)

I wouldn't say a Data Sheet is required, many, if not all contract tubes are supplied without a Data Sheet as they are made to be above a minimum contract spec. Also some commercial tubes (F9800 series tubes) also have a minimum performance spec they must perform at or above in order to be classified as such from the vendor. Since Data Sheets are generally not cheap to get made, if you can find the minimum performance specs for a specific labeled tube, it is usually good to go as I have never seen a company label a tube as one thing when it was something completely different.

[EastCoastShooter]

Excellent write up. I would add though that having a white phosphor tube is not a deal breaker. The new filmless WPT from L3 are apparently top notch and many people seem to be switching over from green if you believe the talk on the NV forums.

[brock0]

Good info thanks.

Aside from the device itself, can you talk about required accessories? Mounts, lasers, counterweight, etc.

I have always been curious - can you use NODS with full seal goggles? Or would they sit too far away from the eye? Do you need low pro eye protection like Oakley M frames, Revision Exoshield, Boogie regulator, etc. ?

[Desmodus]

Originally Posted by brock0

Good info thanks.

Aside from the device itself, can you talk about required accessories? Mounts, lasers, counterweight, etc.

I have always been curious - can you use NODS with full seal goggles? Or would they sit too far away from the eye? Do you need low pro eye protection like Oakley M frames, Revision Exoshield, Boogie regulator, etc. ?

Having low-profile eyewear certainly helps but you can easily use full-seal with NVG's, all you have to do is adjust the mount so the NVG sits in front of your eye correctly. I have comfortably used NVG's while wearing ESS goggles and I know people who have used them while wearing bulky JT paintball goggles.

[brock0]

Originally Posted by Desmodus

Having low-profile eyewear certainly helps but you can easily use full-seal with NVG's, all you have to do is adjust the mount so the NVG sits in front of your eye correctly. I have comfortably used NVG's while wearing ESS goggles and I know people who have used them while wearing bulky JT paintball goggles.

That's great to know, thanks very much.

[Zack The Ripper]

Slight correction to one of your acronyms:

NOD = Night Observation* Device

[BenG]

Thanks for the feedback will update with those corrections, and will add a asscessories topic

[Datawraith]

Originally Posted by Zack The Ripper

Slight correction to one of your acronyms:

NOD = Night Observation* Device

I thought both were correct acronyms. I've seen them used as both before in literature.

[ShelledPants]

Originally Posted by Datawraith

I thought both were correct acronyms. I've seen them used as both before in literature.

Night Optical Device and Night Observation Device are interchangeable.

[viraL]

Originally Posted by brock0

Good info thanks.

Aside from the device itself, can you talk about required accessories? Mounts, lasers, counterweight, etc.

I have always been curious - can you use NODS with full seal goggles? Or would they sit too far away from the eye? Do you need low pro eye protection like Oakley M frames, Revision Exoshield, Boogie regulator, etc. ?

Counterweights can be as simple as you need. I have lent 1911 CO2 mags to Deltastone for a counterweight for a dual PVS14 mount. Required 4, but it worked.

There are quite a few companies that make them.. very popular are the EOG counterweights. They are not a requirement but anything to help balance them out works really well.

Mounts - you can go as simple as USGI J Arm. There are a bunch of upgrade options after this.. old norotos titanium mounts, AKA2, INVG, then we go into Wilcox territory with L4Gxx models, standard for "best system for monocular" these days is L4G24 with Wilcox J Arm or Norotos Dual Dovetail.

The USGI J arm works fine for many airsofters, even better when you have ESS or low profile full seal - just jam the monocular against the goggle and it works pretty good. Obviously upgrade options are better, more stable and more reliable, hold the NOD at a better angle when flipped up, and in the case of the INVG gives you different ranges of motion with the arm to circumvent vehicles (low ceiling) etc. No best way - but everything is better than a J Arm.

As far as lasers go - they are not a requirement but damn they are cool. Anything class 1 FDA approved will be good. I believe the current standard is 0.7 mW for eye safe lasers. LDI products like OTAL ITAL etc are good to go. PAQ4C is only eye safe mode, PEQ2A/PEQ15 etc all have high power eye melting modes, but also eye safe training modes. Illumination is a great function too from some models like DBALs.

Generally having white-light and IR available is a plus. Inforce WML is the cheapest to do both of these, higher priced version do it a bit better. Surefire has many options (I use a surefire M952V, love it).

Weapon sights are a great investment as well. Stuff that has an NV mode (eotech, aimpoint, holosun) are critical. This will allow you to engage targets WITHOUT throwing your laser on and giving away your position. This is the standard now for ontario airsoft, a lot of players are moving away from using Lasers as primary aiming device, and for good reason.

Hope that sheds some light on some of your questions brock0

[BenG]

NOD night optical or night observation are interchangeable, ITT was intended to he IIT, as said earlier ITT is a company

[brock0]

Originally Posted by viraL

Counterweights can be as simple as you need. I have lent 1911 CO2 mags to Deltastone for a counterweight for a dual PVS14 mount. Required 4, but it worked.

There are quite a few companies that make them.. very popular are the EOG counterweights. They are not a requirement but anything to help balance them out works really well.

Mounts - you can go as simple as USGI J Arm. There are a bunch of upgrade options after this.. old norotos titanium mounts, AKA2, INVG, then we go into Wilcox territory with L4Gxx models, standard for "best system for monocular" these days is L4G24 with Wilcox J Arm or Norotos Dual Dovetail.

The USGI J arm works fine for many airsofters, even better when you have ESS or low profile full seal - just jam the monocular against the goggle and it works pretty good. Obviously upgrade options are better, more stable and more reliable, hold the NOD at a better angle when flipped up, and in the case of the INVG gives you different ranges of motion with the arm to circumvent vehicles (low ceiling) etc. No best way - but everything is better than a J Arm.

As far as lasers go - they are not a requirement but damn they are cool. Anything class 1 FDA approved will be good. I believe the current standard is 0.7 mW for eye safe lasers. LDI products like OTAL ITAL etc are good to go. PAQ4C is only eye safe mode, PEQ2A/PEQ15 etc all have high power eye melting modes, but also eye safe training modes. Illumination is a great function too from some models like DBALs.

Generally having white-light and IR available is a plus. Inforce WML is the cheapest to do both of these, higher priced version do it a bit better. Surefire has many options (I use a surefire M952V, love it).

Weapon sights are a great investment as well. Stuff that has an NV mode (eotech, aimpoint, holosun) are critical. This will allow you to engage targets WITHOUT throwing your laser on and giving away your position. This is the standard now for ontario airsoft, a lot of players are moving away from using Lasers as primary aiming device, and for good reason.

Hope that sheds some light on some of your questions brock0

That is a lot of great info, really appreciate it.