I have a set of pvs-7’s. Gen3 non auto gated. I am trying to find the pros and cons of adding a LIF to them. I don’t know if I need it. I want to protect my goggles, but I also don’t want to waste money.   Do you put t on and leave it?   Does it affect in anyway the usefulness of your goggles?

Thanks

An additional thanks to stonecutter for having me realize I hit the back button to far and made my original post in the EE

They look cool.... That's about all they will do for your PVS 7 unless you work with high power 1064nm lasers.

They reduce the amount of ambient light going into the objective lens, which is bad. They block high-powered US military lasers, which is good if your tube would otherwise become exposed to them. There is probably very little chance of that happening however, even without one, unless you're around friends with real PEQs who are kinda dumb with them sometimes.

I leave mine off.

I thought it was just things like tank lasers? If it blocked 850nm then it would block the illuminator too, right?

I use it as a sacrificial lens

Designed to block high power YAG lasers from things like rangefinders and target designators. Minimal attenuation in the ~800-900nm range where IR illuminators and lasers operate. Also blocks the second harmonic (532nm) of YAG lasers which means a LIF completely blocks green lasers.

As you can see, it depends on your mission.  If you just want a sacrificial lens (highly recommended), get the GI one, or any good screw-in camera lens.  If you think you might be exposed to high-power lasers, then the LIF is a good idea.

There's a really good thread with stuff like this and lots of other info in an old thread called do's and don'ts of NV.

And ......there's the cryptic "I'd tell you but I'd have to kill you" comment I was expecting when I opened the thread.

It seems pretty straightforward... It's a filter that blocks a certain wavelength. I can't imagine what "other" uses it might have that require a read-on to know. Maybe they can decipher alien languages or they secretly house nuclear launch codes...

You could also screw them into the ocular lens to remove the green hue.....kinda a poor man's white phosphor image.

Thanks for all the responses.   Based on what I have heard here and manages to find online I think I am leaning towards one of the PHOKUS Hoplite covers instead.

i've done this

It’s even cooler on thermals.......or would that be hotter.......?

Whatchu talkin bout Willis?

Well that is one POV.  That would depend on your estimate of the situation and how likely it might be that things change in your life time.  I laugh every time I hear the phrase "for real world civilian use" or similar.  That is a very institutional out-look of some one deep into the mil-industrial complex.  Not that it's necessarily wrong, just very one-sided.  Here is another.

If you're the guy on the receiving end of troops with high-powered targeting lasers, then you damn-well do have a (very pressing) need for them.  You can argue the legality of it, or ITAR, or whatever you want, but to say there is no "need" is wrong.  You can also argue that whoever is on the receiving end, deserves it, by god; and in some cases, you'd be correct, but in others, not so much.

But I would contend that yes, in some parts of the world, civilians do have a need for LIF's.  And in some cases they are good people, who through no fault of their own, have come up against some nation state's troops that want to control them.  I would also argue that however unlikely it seems at the time, that something similar could happen in this country, in the future.  Why people still think this country was divinely inspired and protected, and "that can't happen here" (all evidence to the contrary), is beyond me.  But that is one opinion, and as always and forever, YMMV.

Suffice it to say, if you think there may be a good reason to have them, then by all means, you should obtain and use them.  Yes they may be "gray market" but unless you are a part of the .gov or their suppliers, you probably don't have a reason to worry about it.  As a side point, anyone who has been in any "military" town, and seen all the stuff guys trade in pawn shops, well, it is what it is.  Not defending that, just saying it exists.  Of course anyone who is a legitimate dealer in this stuff would encourage you to buy from them, rather than (possibly dubious) surplus.  Or parrot the party line of "not for civilian use" because that's the politically correct response, for them.  Granted.  But if this might be mission essential equipment, in your estimate, then you have to make that decision for yourself.

Or, if you just need a sacrificial lens, use something else.  Perhaps less controversial.  To the OP, yes, any additional lens will effect the clarity of the picture somewhat.  But depending on the circumstances, may be required.

Well said!

Thanks you again to all that have posted here.   I ended buying one.   Will try it out.  I also learned about the redneck method of the phokus adapter.    I am going to give it a whirl before buying the real one.    This is truly a great place to gain knowledge and put things to good use.

Yes it is; I have learned so much about NV from here, both theory and also practical app.  Augee commented on this thread in another post so I wanted to add:  the SME's around here are plugged into the gov't and vendors, to one degree or another.  Out of necessity, they must walk a fine line, between releasing what info they can to support their marketing effort, and holding back info that may not necessarily be classified, but is sensitive to the gov't or the vendor.  We benefit from their release of knowledge, and access to NV equipment.  So I don't want to bang on them too hard; it would be an ungrateful SOB that would take advantage of all they offer and then turn around and mother-fuck them, just for drill.

But on the other hand, you sometimes get guys who have been too long in gov't service (or vendors to them), and get this institutionalized outlook on things.  They start to believe in this "us or them" mentality, forgetting who is supposed to be serving who.  The current deep state is an excellent example of this. I understand the necessity of opsec in some cases concerning NV, but oftentimes it is accompanied by an attitude that is arrogant or condescending.  While I acknowledge the need for opsec, I do not believe this knowledge or technology is wasted on civilians; that we don't have any need for it.  I have watched the sad decline of this once great nation for the past 50+ years; our present course is not good.  My estimate is that we could have a very compelling need for it.  Whether you agree or not is not the issue.  Rather, that if an individual sees a need, he should plan accordingly, regardless of what others may think.

So I would submit, you may require some opsec concerning NV, but it is for different reasons than my "need to have".  Keep it from your enemies, sure; keep it from your competition, well, yeah I guess.  Keep it from me because someone else decided I don't need it?   Unacceptable, IMHO.  This displays a fundamental lack of trust in the people you are suppose to be protecting.  Granted, a large percentage of them have demonstrated they can no longer be trusted.  Therein lies the problem.

Did not mean to demonstrate massive thread drift.  Apologies.

Do you realize that the forum is accessible to anyone with an internet connection?

Assuming you are a US Person, ITAR may not prevent experts from delivering information to you, but it might prevent them from delivering information to the entire world at the same time.

If the info is ITAR protected, it would be a crime to post it here. This is true whether or not it's already been said before, or nobody thinks it's a big deal, or nobody ever gets busted for it.

I think it's a sound business strategy to not commit crimes. I also think it's a smart if someone knowledgeable on the subject steps in to let us know when we're getting too close to the line. Because I don't read ITAR rules, but I certainly agree with the intent of it.

On your topic of trust, as an American you have access to all the Gen 3 equipment & technology you desire. Stipulation being that you don't transfer the items or technology outside the country, partly to protect the overmatch of US forces against all enemies.

Is that so unreasonable?

Not at all.  And I have said as much.  I just take exception to someone saying I don't have any "need" for this kit.

Yes I am a US citizen, military brat from birth, served active duty and reserves, thank you very much.

Yes I realize anyone can read this stuff.

In NV, there are many gray areas.  As I said, things that may not be necessarily classified, but for various reasons folks don't want released.  LIF's fall into this category.  While not stated in open forum, exactly all they do, we can take a pretty good guess at things.  So if you see a possible future need for them, then get them.  If not, just get a regular filter, for cryin' out loud; that is the whole point to this thread.

People within the industry must live by the rules of the trade.  Sometimes there are very good reasons for these restrictions, sometimes not.  But anyhow, that's how we have to play the game, to get access to what we can.  I may not like it, there may or may not be a good reason for it, but there it is.

Yes sometimes we are discussing things on the cutting edge, and sure, there should be some filters applied.

Your argument about our enemies gaining access to this stuff doesn't necessarily hold water.  What about all the equipment they have obtained through battlefield pick-up?  Do you really think that stuff doesn't end up in our enemy's R&D departments?  They sold the tail rotor off a stealth Hawk to China for fucks sake.  You can say the law is the law, ok, whatever, but in this case it may be locking the barn door after the cow got out.  The laws may be pretending to protect a lot of technology that has already gotten out.  But in the case of the newer stuff, yeah it needs to stay classified.

David knows all about the LIF's. they were made in China anyway lol. Ask him for the story.

Short answer: don't use them.

Do civilian legal lasers not damage NV?

They do.
I was wrong about the PEQs. Any beam it "sees" will harm it if pointed into the objective (or even if indirectly exposed to intensity too great). That's one way to get a spot burned onto your tube. They start off at the temporary level, but greater exposure is permanent. Obviously a higher power laser will harm it faster. That's why the LIF exisits... for the badass Abrams rangefinding lasers and such. How well does it block that stuff? I have no idea.

So, it would seem that a LIF would be a good investment.  Why have NVG if you can't use your weapon and the best way to use your weapon with NVG is with a laser.

The LIF doesn't block the frequencies used in common military (infantry) and civilian lasers (unless they're green).

They'll also block all green lasers according to this.

Get a screw in ir camera filter and avoid the debate entirely. Plus I like screw in camera filters because they can act as a sac lens and you still retain the ability to use the friction mount on a magnifier. Traditional type sac lens you can't  use magnifier.