A common paper like Ilford MG RC Warmtone cuts off hard at 550nm

http://www.ilfordphoto.com/download....0207232634.pdf

The red led rope light here has a 630nm peak.

http://en.wikipedia.org/wiki/File:Re...ED_spectra.png

shows a spectrum graph of three LEDs including a red one, pretty sharp output that should not pose a problem. I think it's a matter of either testing like Thomas has done or comparing spectrum graphs before purchasing.

http://www.orangetreetrade.com/shop/...nch-p-666.html