720nm IR Filter on Objective Lens of PVS-14

SkyPup

SkyPup

New member
I had a 30mm 720nm IR filter for one of my cameras for special effects photography and thought that I would try it out on my PVS-14 objective lens tonight to see what it would do.

It is a very very dark lens that you pretty much cannot see through during the day since it blocks out almost all of the visible light spectrum.

Apparently it has zero effect on the input to the PVS-14 through the front objective, as the night image is just as bright as without it, however it appears to me that the focus of the PVS-14 is now improved?

I can still see my IR laser just fine and my 850nm IR Illuminator works as always.

Here is the lens I am using:

http://opteka.com/r72ir.aspx


Here is where you can get one:

http://www.amazon.com/Opteka-720nm-Infra...8081&sr=8-1



Human%20Vision%20and%20PVS%2014%20Vision.jpg


This above graph shows the human visual spectrum from about 400nm (purple) to about 720nm (dark red) that we see during the daylight (curve on the left), compared to the light frequencies that are picked up by the PVS-14 image sensor at night from about 600nm (green-yellow) to over 900nm (IR) (curve on the right), everything over 720nm is invisible to us as it is infrared light....


Now, this graph shows what various substances are irradiating IR at night when it is dark out and there is no visible light, only infrared light. Everything on Earth is irradiating IR light at night, different substances emit different levels of IR all night long.


Night%20Vision%20Materials%20Reflection.jpg


You cannot see anything through this lens when looking though it during the day unless you hold it up and aim it at the sun, and that is NOT recommended as all the IR will still be blasting though it into your eyes...

720%20IR%20Filter.jpg


720%20IR%20Filter2.jpg


By eliminating the visible light you cut down on the bandwidth of light going into your lens thus reducing chroma distortion, thus improving the focus.

I can report that the IR Filter on the PVS works exceptionally well at dusk and twilight which used to be the most difficult time to use the NV before I installed the filter...it also works well with non-NV red dots, scopes, and lighted reticules....
thumbup1.gif
 
The improvement is sharpness of focus is readily apparent. I am leaving the IR filters in my two PVS's all the time now, they work especially well at both dusk, twilight, and dawn when without the filter the PVS was mostly useless, now it works like a charm and there is quite a bit of game activity at those distinct times!

Quite often, folks scoff at science taught in school saying it is useless in daily life. But, if you pay attention you realize how it is all around us and how useful it can be.

From brewing beer to understanding the specifications for a rifle scope and how it affects what you see to putting a filter on a NV scope.

It is nice when things work like they are supposed to according to standard scientific principles.

Sometimes an improvement is only a couple of nanometers away.....
 
This IR Filter works great,

With my SIG 556, Eotech 552, PVS-14 and Sony 2X Telephoto with Barnes 70 grain TSX, one shot kill on a coon @ 225 yards tonight pitch black out no stars or moon, heavy overcast.

Shot him right through the shoulder where I was aiming, could have used the DBAL-I2 IR laser....

556%20&%20FLIR.jpg


Coon.jpg
 
Last edited:
Nailing a coon in the pitch black at that range spot on gives me plenty of confidence for next time I meet up with some hogs or 'yotes in the coming weeks ahead....
 
Skypup,
What size filter did you get and does it just screw into the objective lens of your PVS? Thanks.

Nevermind. I went back and read your original post again and see that it is 30mm.
 
Last edited:
It is a 30mm filter that screws into the objective lens on the PVS-14, I am leaving mine attached all the time.

See my above posts for hyperlinks to where you can purchase it from Amazon....
 
Skypup I just got the lens today. You told me you could use this lens with the 3x magnifier...Do you mean only the slip on cover that comes with the magnifier or does this lens come apart and you can screw the pvs14 3x magnifier into the pvs14?


Thanks
 
You can screw the 3X magnifier into the external threads on the IR filter once the filter been installed into the objective lens of the PVS-14, you have to unscrew the the slip-on portion of the USGI 3X magnifier first though.
 
YES its dark. Its the same lens you would take a regular flashlight or spotlight and shine so the nightvision would pick up...

so i am confused how does this help...I know you said easier to focus and i believe you comments 100 percent.

i cant complete a field test it until after teh weekend. I am assuming it would take bright lights around the pvs 14 and either dim (make it safe) or make it brighter for the pvs 14.


When you say focus improved...with or without the ir light?

Does your reticule of the eotech look better? do you have to turn up the eotech to see it perfect now?

I tested it on the trijicon. It dimmed the center bloom completely.

I looked into my house window with the light on inside the house and it filter that light when using pvs14. So it also stops blooming of bright lights to a point.


so far a great find.
 


Write your reply...
Back
Top