This is a, somewhat odd, question to all you film photography enthusiasts. I took a darkroom class last semester and the instructor told us that things like watch lume won't fog the film or photographic paper. The darkroom timer's lume wasn't exactly the brightest and I noticed most people's watches (if they even had one on) was pretty feint and my Seiko's lume is as dead as a doornail anyway. Since then I've gotten interested in watches and my Laco's lume is pretty bright in a fully dark room. Will this cause any problems? What about tritium watches?