I am going to construct some sort of under the lens shutter / red filter setup for my Omega D2. The plan is to keep the enlarger light on all the time in order to avoid neg pop once it heats up.
My Idea is to mount a second lens board upside down under the one in use. I would do this by putting a pivot screw through the handle on the lens board. What type of red filter will work for this application? Will a standard Red25 work, or will it fog the paper? I plan on doing some tests, but don't want to fork over the dough for a filter that won't fit any of my lenses.