After messing around with night vision a bit, I discovered that the amount of light you let in makes a huge difference in your ability to see detail at varying distances in different light conditions. There are a couple ways of dealing with this:
- Flip-up lens cap systems, such as the Phokus Hoplite or the improved Butler Creek setups (sometimes involving 3D printed components)
- Irises
My RNVG came with a flip-up system with a 3D printed “shutter”. It works well enough, but is not up to hard use. It’s also the wrong color, which offends my aesthetic sensibilities. I knew in my heart that I wanted an iris system. The problem with irises is that the go-to Matbock Tarsier Eclipses are hugely expensive – as in $250 each. While I’m not afraid of spending money when it’s called for, $500 for a couple irises seemed a bridge too far, especially when there had been some complaints that they were so tight that adjustment frequently adjusted focus. If I were using these in a duty context, sure, I’d buy the Matbock solution and then expense it to my unit.
However, with the power of the internet, I discovered there was a far cheaper way of approaching this problem. Here’s the recipe I used:
If you’re in a hurry, you can get the same irises off Amazon for 50% more, but if you use my recipe, it’s ~$50 for each tube. Besides the much more acceptable cost, one thing I really liked about this solution was how I had more finely-grained control over light, and how the sacrificial lens was screwed in (vs sandwiched in my previous setup). The amount of force needed to turn the diaphragm was also just right, and did not affect focus. They also look super cool, and if they get damaged, it’s a LOT less money that I’m out. I was quite impressed with the amount of thread engagement that each piece of this solution also had – the iris and lens are not going to be coming off by accident.
The Hebrew Hammer 