Gra-lab - Phosphorescence
Hi. A little question I always meant to ask about the phosphorescent (glowing) numbers on the face of my good old Gra-lab (my dad bought it circa 1970 and it still keeps perfect time). I've always avoided using it in dark processes (printing, tray-developing film) because I assumed it would fog (particularly film). But at one time it was a pretty popular darkroom timer, so people must have used it in the dark. So what's the deal? Is it just not bright enough to fog paper within a reasonable amount of time? Etc.