Quote Originally Posted by Truzi View Post
That is a really cool idea. I don't know much about safe bulbs, but I imagine there must be some bare red bulbs made specifically as safelights. I'm sure a Google search would bring them up.
There was a range of bulbs with different coatings apt for the various spectral sensitizations of the materials.
(Last year I even ruined one of those bulbs when I cleaned the dirty bulb be means of warm water, totally having forgotten that the coating was made from dyed gelatin.)

Quote Originally Posted by Gerald C Koch View Post
The problem with most red light bulbs that I have seen is that the red coating does not go all the way to the lamp base. Any white light escaping from this area will cause fogging. You would have to cover this area in some way -- say black paint.
The lamps I know have a rubber sock where the bulb enters the metal capsule, to cover any uncoated parts of the bulb.