Justin,<br><br>...and don't forget green, as it enters the debate now. Personally, I'm a "red light" afficiondo, which makes me an antidiluvian these days, I think.<br><br>I'd like to read a authoritative contemporary research paper on the topic. Much of the recent "info" that I have read does not seem to directly address the visual purple washout problem (which is why red light was first favored). Instead, the articles I have seen talk about "dazzle" (intensity), which is a whole 'nother topic - that's a mechanical (iris) aspect. Too bright a light of any visible color will cause the pupil to contract, of course. IMHO, the major mis-direction comes from our current fascination with monochromatic LEDs that can be rather intense if the LED proper is viewed.<br><br>My pupils re-dialate very rapidly; visual purple takes quite some time (average 20 minutes for most folks) to recover. I experimented with a red photon II in January this year and found it easy to dazzle myself with it BUT my night vision was not affected - when I stopped shining the light in my eyes, I could see in low ambient light within a few seconds. A filter-equipped mini-mag flashlight did not dazzle me as badly as the LED. A better test will be to have an observer note my pupil size, but I didn't think of that at the time.<br><br>I have been skeptical of the efficacy of blue for preserving night vision. My experiences with blue vs red came late in my Army career. I found that blue washed me out a little - not as bad (totally) as "white" light, but noticible to me. Red does not adversly affect my night vision. At that time, the lamps were incandescent and the color was established by a filter. Where I was, I am certain who advocated the blue vs red and am certain why they did - it had a lot to do with distinguishing certain colors and little to do with preserving night vision - sort of a sop, at the time, to not using white light. However, there may be some merit to the blue - surely it is better than white light. My observations were hardly scientific. And monchromatic blue light from LED sources may have less adverse effect than the multi-spectral light from filtered incandescents. As I wrote, I'd like to read a good research paper on the topic - one that deals with both night vision (visual purple) and dazzle (iris).<br><br>I think Chris K. may be an advocate of blue light - Chris, will you chime in here with your experiences, please?<br><br>Regards,<br><br>Tom