I would like to know what kind of effect it would have on night vision riflescope if it was mounted on a rifle without a flash suppressor.  When fired would the bright flash damage the optics or just temporarily knock the system offline?  

How does a person sight one in?

Are there any kind of filters designed to be placed on the objective to keep out harmful bright light like a welders lense would do?

Thanks,
Wes

Wes, you have to many variables to give a complete conclusive answer to your question, I would depend upon many factors - who's the scope manufacturer , which generation/technology, what kind of flash are we taking about, just to many variables.

I will tell you of my experience, I have several russian NVD - first of the 3 tubes I have each has a different sensitivity to lights. one has single tube and the other has double seperate tubes.  I was finding it interesting that in very dark enviroment one of the tubes will go to static while the other tube by same manufacturer goes to just black.  

As to lights and their effect - my equipment is early military or civilian generation 1 - I would rate it poor choice for serious long term use.  I have noticed fisheye (distorted image) and if you point it towards a med to high power light source it just goes white (I think long term exposure would damage the unit), It stays white for many seconds. I have not had it go to white when used with gun fire from behind the weapon but I have not had it pointed directly at the muzzle either from in front or from the side, I always use from behind looking towards the target area.

You will notice that the red laser's appear as a solid beam of light (like a green laser does to your eyes), and the IR laser's do as red laser's do to normal eye's with NVD (IE you only see where they land on the target, provided it's not dusty).  

If you want to use one for serious business you should consider either red dot sight compatable with nightvision equipment and goggles or good 3rd generation NVD with automatic cut off's built into it for light flashes from auto's etc.   I myself  like the goggle & laser approach as it give more flexablity to me and I don't have to point a weapon to see if it's a target or not.

You ask about how to sight a NV scope in - it's the same as any other scope use the adjustments to bring the bullet impact to point of sight at range you want it sighted in at - laser was nice as I just put mine in rifle vise used reddot scope to put whole thing on target (flashlight on target) - tuned off flash light  -put on night vision goggles and aligned laser dot to where red dot was- fired for effect- hit target were dot was and was done. I would suggest LED IR lights in several levels if using for hunting at night in woods you may not get enough light to see well (but much better an with normal eyes and not flash light)

Some of the systems do take other filters and lenses and camera adaptors - I have not seen one as you describe but newer equipment have a setdown/cut off function for when too much light reaches the objective.

Best way to sight in a dedicated NV scope is with a laser boresighter, IMO. Another way is to just shoot close range to get on paper then move out to longer ranges for a fine zero. Kinda like you do at the range, only in the dark and checking each shot up close to see where it hit.

A muzzle flash will cause a GenIII scope to momentarily bloom in the lower region of the screen. It immediately recovers and it is not as bright a light as something like a streetlamp. Lesser capable scopes bloom more and will take longer to recover.

The lense cap probably has a tiny hole and the scope will actually work with it on in high light environments but I wouldn't recommend operating in those conditions. It has been said that repeated exposure to light will reduce the life of a photomultiplier tube. Couldn't tell ya if that is folklore or the truth.

A lot of very informative information here...thank you very much guys.

Thanks,
Wes

My ar with no flash hider and my cheapy ATN causes the scope to automatically turn off.  I'm currently working on getting my barrel threaded for a flash hider.  I don't want to ruin the scope.

i have had many gen3 american scope all of them are sensitive to muzzle flash but that s what the ABC (auto brightness control)  system is for, it's shut the scope off for a fraction of a second.

the 16" barrels produce much more flash than the 20"ers and almost always cause the scope to flicker.  in fact, my 4x raptor would not even shut down when using a 20" barrel and Q3131A ammo. XM193 is a different story though, more flash. the pvs17 seems to be more sensitve to muzzle flash though.