Surefire Beam Filter

Why are they sooo complicated? I have the blue one (FM36 I Think) and have often wondered why it was sooo 'sophisticated' not the locking mechanism so much, as the lens, mine has a mirror finish on it. As opposed to a lot of the blue plastic lenses most companies use. Why does it have to have a mirror finish? Is it meant to signal in emergency? Does it have better blue rendition? I figured someone here would know!

Thanks! I think this is the right forum, if it isn't thanks for moving it..

There's much more to a beam filter than just colored plastic.

There's probably an AR coating and who knows what else goes into it.

I wonder if the filter is also tempered Pyrex.

There's probably also other manufacturing processes to make sure that the optics retain their properties and resist environmental effects.

Look at the price difference in the IR filters, you know it's more than just a cheap plastic lens. But I have no idea what/how they are made.

Where's Size 15's? He'd know something

SureFire coat their red and blue BeamFilters to ensure the most amount of red, or blue light is allowed through and the rest of the unwanted light is not. The coatings include anti-reflective coatings.
These aren't the most durable of optical finishes so avoid scratching them.

What are they made of? Lexan, Pyrex or some special material?

And what makes the IR filters different? I'm guessing their coating?

Very interesting, something I never thought of before this thred.

The red and blue are [tempered] Pyrex AFAIK.
The IR is not Pyrex glass

The most effective filters I've used (I've tried many) are photographic lens filters. The ones below fitted to a Dereelight DBS and a Wolfeyes Shark 10/24 HID are Hoya Y2's

Interestingly, by cutting out the ultraviolet & blue wavelengths of the beam its easier to see objects at distance, particulary through a telecopic sight. I think this is because our eyes are more sensitive to the blue, any thoughts?

i havent played with any of the surefire filters but from what i have seen of them it almost seems like they are dichroic filters. so instead of absorbing the unwanted wavelengths and creating heat, it reflects them back into the light. if you hold it out and shine a light on it from a distance and it reflects a different color than what the filter is meant for then it is dichroic.
for example:
if it is a red filter then the reflected light should be cyan
if it is a blue filter then the reflected light should be yellow
if its a green filter then the reflected light should be magenta

Hint: for any of that color math stuff there is a simple chart here:

....C. M .Y
R .x
G .... x
B ........ x