Just did some testing because I wanted to illuminate my front yard - My goal was to use the highest wavelength possible so that the LEDs aren't in the visible range.
Talking to my local supply store, they sell IR LEDs made by "Knight Lite". You can find the technical specs here: http://coolacid.net/images/Knight_Lites-IR.gif
I grabbed 4 of them, one of each wavelength and tested from the top. My first one: KIE-6305-1P worked like a charm - I couldn't see any glow and it lit up my face like a flash light. Of course that's in the 940nm range, Since I have them, when it gets darker and I can do more testing, I'll pop open the 7305 (640nm) and report back on both LEDs.
Update - Dark enough to test both LEDs well now. Both the 640nm and the 940nm lit up the room quite well, although multiple LEDs will be better (all tested with a single AA battery connecting the leads directly to the battery).
It should be noted that the 640nm water clear had the full red glow you normally see. In the dark, the 940 did have the red glow too, but not nearly as much.
Having said that, the 850nm devices *should* work with the cameras.
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Topic: IR Sensor wavelength (Read 5700 times)