Since Iím currently darkroomless (but working on it) when I answer questions like this I forget others have different working methods. I develop in drums rather than by inspection, therefore I can have a brighter working environment than those that develop by inspection. Les has made a valid point regarding lamp start-up, however my Duka 50 has a slider to dim the lamp mechanically, that is by covering the lamp, rather than dimming it electronically, now I know why. When Lith printing, which has to be done in open trays, I used an old fashioned 15 watt red light which I switched off for the first 20 minutes of the development cycle, I switch it on every few minutes just to make sure Iím still alive. The important thing is to do safe light tests to ensure that your paper is not being fogged.