Since I just received the clock, I haven't had time to test it yet. But the light sensibility of VC papers doesn't expand beyond 580 nm. Red leds have a very narrow spectral band above 610 nm. My experience confirms this. I have several darkroom lights based on red LEDS. Even cheap bicycle taillights. In practical use they are all absolutely problem free. So I'm confident that testing the clock will give similar results.
The old style red incandescent light bulbs were much more dangerous since they only were painted full spectrum lamps. But even with those lamps I couldn't detect any problems up to 10 minutes exposure in my darkroom. Ofcourse you should respect minimum distance, and have an absolutely lighttight darkroom.
Last edited by argentic; 06-19-2013 at 11:09 AM. Click to view previous post history.