Infrared Pass Filter

I’m looking for a good infrared pass filter in the 840nm range. I’ve had some success in the past using filters from here: in conjunction with a black and white infrared sensitive camera (multi-touch setups, etc). Unfortunately I don’t always have completely dark rooms to work in and must be prepared for varying light situations, so I’m looking for the best solutions possible. I unfortunately don’t have unlimited resources to buy and test every camera / filter / LED configuration, so if anyone has any resources, tips, or anecdotes, I’d like to discuss them!

did you ever try a piece of a photonegative film?
i was confident with the results.

for sure you know

somebody uses CD-Rs for filtering:

Hehe, yes, the first prototype was a ground down webcam lens with photonegative paper. I’m trying to move away from the “dirty hacks” (even though they are great) to something a little more heavy duty.

I know of the nui group, I used it as a resource for building my prototype, but kind of forgot about it, thanks for reminding me!

Have you tried emailing lee filters through their website? If you ask them nicely they’ll send you a swatch sample book which has hundreds of samples of coloured filters. They are big enough to fit over your average CS lens size so you can test away to your heart’s content. When you find the right combo you can buy one of their holder frames for a more permanent solution.

The brilliant thing about the swatch book is that it has a graph for each filter showing you what wavelengths are let through. Makes it very easy to choose which ones to superimpose to get the right amount of blocking effect.

Interesting, I might have to give that a shot as it sounds like it would be extremely useful. The sample book includes IR pass and/or bandpass filters in the Infrared range?

go ogle all congo blue and primary red.