Originally posted by tuco Over the years I have collected a lot of colored filters in various diameters for my BW film gear.
My problem is that a lot of the monochrome work I have done over the years typically involved Rangefinders, and the lenses for RF cameras typically never have filter threads that went beyond 62mm*. I have done some experiments with knocking out the glass in an STC mirror box mounted filter and replacing it with filter glass from a Nikkor O56 filter that had a damaged frame. That works quite well for wide angles but due to flare issues it is ill advised to use these mirror box mounted filters with telephoto lenses.
*and even that is pretty uncommon. The Leica Noctilux 50mm f/0.95 has a filter thread of 60mm which is quite possibly the most infuriatingly uncommon filter diameter in history.