@citizenjoe They're advertised as 850nm and I have an 850nm filter for the camera, so hopefully both companies are telling the truth.

fingers crossed on that one.

@woland said:

Roscolux 19 (x2)) Roscolux 83 (x1) Roscolux 90 (x1)

 It's inferred above, but the gel option will NOT work with most LED lights [edited - sorry]. 

That said, the cheap amazon type options do work well. Just make sure that the wavelength of light output from the fixture matches the wavelength that your camera is looking for.

Cheers,

Hugh

@woland I found a pretty low cost IR led floodlight that's made for CCTV applications. 

I'll have a little play around with them and report back in case my findings are useful to anyone. I suspect I'll need to improvise some barn doors but otherwise this seems like a path to something.