Another ingenious build, Justin. Can't wait to see the finished product.
Interesting thought. It would reduce throw since it reduces the light by 1-2 stops like a neutral density filter.
I have one and I think I’ll take it out tonight and shine the brightest flashlight I have (MC-E) and look through the filter and rotate it and see if there is an interesting effect.
I’ll try in in front of the lens as well but my light is bigger than my filter.
I have a feeling it may not do much other than reduce the output. In the daylight the greatest effect is 90 degrees from the sun.
The other benefits are reducing the reflections off of other surfaces that you are trying to take a picture of.
I’m not sure how effective it is over the light source in the case of a flashlight but it should make the rays oriented in just one direction so who knows?
Good thought!
Justin good idea as well to use photographic filters in the first place!
I have a circular polarizer that cuts less than a stop, I may try that too.
Please report back !!!
I was outside (rare clear weather) doing some astronomy stuff and tried the polarizer with several different lights but other than reducing the output I couldn’t seen any positive changes.
Maybe I’ll try it again sometime in fog or rain but so far not much change.
Were you able to try yours out?
No...I haven't found it yet. 
Well, why not change it all up in the middle of the build? The mail lady is in love with my smile. She brings me stuff I didn't order. I hope someone else is not waiting for their order, since she is delivering it to me...
What better for an SST-90 reflector than an SST-90 emitter? Well now I have one to put in, so I'm changing the build up with an SST-90 and a driver and using a Red 3D Maglite. I am going to put 4 Sub C NiMHs in it (rated for 35amp high draw) and see what will happen.
So..........
Rather than trying to change all the info in the first part of this thread, I think I wlll consider this thread closed and start a new one with a 3D Mag and an SST-90 emitter and let this thread die of old age...
Great work 