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Infrared Flash

Started Dec 16, 2017 | Discussions thread
ProfHankD
ProfHankD Veteran Member • Posts: 9,147
Re: Infrared Flash

petrochemist wrote:

At night at least if the flash has an IR filter there's no need of one on the camera.

I've used IR perspex with an off camera flash & a simple camera filter held infront of the pop up flash by means of some suitably cut foam.

There is the possibility of the flash overheating if fired repeatedly but it works OK otherwise.

I would be concerned with slapping an NIR filter directly on a flash. People often don't realize just how much power is output (for perhaps 1/1000s) by even a wimpy little flash, and a NIR filter is going to block/absorb most of that energy. Can't be good for filter life, etc. I'd probably 3D-print a spacer....

Typical digital cameras are about 7 stops less sensitive to NIR than visible -- the green channel is usually even less sensitive than red or blue. If it's dark enough that you're underexposing the background by significantly more than 7 stops, no filter needed. Keep in mind that the best cameras have about 14 stops of DR, so there will still be plenty of visible light sensed and recorded.

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