OringinalGeek wrote:It's been a long time since my field theory classes, but I believe the problem isn't photons. Most digital designers forget about EMI problems. We use "standard" Solutions to solve EMI. One poster talked about his experience with Xenon flashes & how they're triggered. This is the real culprit I suspect. The fast rise time that triggers a multi spectrum signal ( think Fourier Transform). The Raspberry Pi 2 shown is a bare board so it's probably quite susceptible to EMI. Shielding it from light won't help (as the bluetac experiment failure showed). Notice also too that there seems be some distance sensitivity as well. The interference path isn't via conduction through power cord or rails, it's through radiation, not magic photons. I suspect if you used some kind of (grounded) shielding it would make the problem go away. Longer term, the right capacitance on the right signal lines might be the solution.

STrRedWolf wrote:I really can't see how bluetac would be safe for operation of the Pi though.

• Don't photograph your Pi 2 with a Xenon flash (just turn it off and shine a regular light on it)
• Put it in an opaque case, or cover the affected areas with electrical tape (don't use Scotch, masking, duct, or Duck-brand tape)