Cheap Adjustable Iris Night Vision Filters

4 min readJan 20, 2021

Disclaimer: These are definitely for range ninjas and LARPers. The adjustment knob is VERY flimsy and unscrews easily. If you’re doing something more serious, get the real Tarsier Eclipse. Also, I’m terrible at dremeling, so don’t hate.

Ever since I found out what the Matbock Tarsier Eclipse NVG focus rings existed, I wanted them. At the price of ~$250 per unit, I decided against it. There are many different quick focus lens caps in the night vision industry. There’s the PHOKUS Hoplight, which is a quick flip up and focus lens cap. Many people have just drilled butler creek caps to do the same exact thing. The Matbock Tarsier Eclipse is the most recognizable out of all of them, as it’s a literal iris that opens and closes via a quick rotation of the front lens filter. As many of you know, I’m an avid LARPer (Airsofter), so sometimes things do get shot towards me, and no one could definitively say that the Eclipses were ANSI rated.

The on-the-cheap-alternative

I’ll give credit where credit is due; I’m not the person who came up with this first. A fellow night shooter, who coincidentally goes to the same night shoots I do at URC in PA, posted this on Airsoft Night Vision Users. Follow him on Instagram: @_mschiano . At any rate, when he posted, I instantly went out and bought the adjustable Adjustable Iris Aperture from Amazon.

This is just a quick way I installed them; there are many different ways to do this; I just wanted the ANSI-rated glass in-front of the iris to protect them from BB hits.

Required Items:

Adjustable Iris Aperture Diaphragm
ANSI rated filters from Claude Riccoboni (contact him on Facebook). Disregard this if you don’t have to worry about projectiles flying towards you.
Butler Creek 9a
Dremel or cutting instrument
Some Tape
Patience

One:

Remove the small adjustment levers on the iris.

There are small flathead indentations at the top, and you can use your fingernail or a small screwdriver to unscrew it.

Two:

Cut your 9a cap

I used a label to draw a makeshift cutting guide. Just figure out how to line up the cut you make on the cap with the full distance of adjustment.
Cut your cap with a Dremel, box cutter, or Exacto knife. Sand it smooth.

Three

Placement

Using the filter, I pushed that through the top of the cap, so it’s even with the end.
Push the iris into the lid so that the adjustment section is aligned with your cut.

Four

Fitment

I use no residue duct tape so that you don’t have glue on your night vision unit if you remove this whole contraption later.
Use a bit of tape to make up for the lens cap’s diameter in relation to your PVS-14 front optic.
Press on firmly, making sure your caps are aligned so that when they flip open, they flip up; don’t have the caps flip down.

Done. Clean up your mess.

This was pretty cool, and now I can focus closely without any problems adjusting my focus on my night vision unit. I can also adjust for changing light conditions manually. Super cool. If you want a little more security, you can always use glue for any of these steps.