If you are going to contact print to platinum, I suggest blowing the slide up in a regular enlarger onto a sheet of Plus-X or something in total darkness, or try to mount a 50mm enlarging lens with a reverse mount and shutter unit on an 8x10 camera if you have access to one. You shouldn't use orthochromatic films because you'll distort color a lot. I haven't tried using digital approach to make internegative, but it's a plausible approach, I think. I would prefer Plus-X rather than TMX because of easier handling and greater depearture from ideal reciprocity law meaning you are less likely to fog. Hope this is of some help -- Ryuji Suzuki (Boston-Cambridge area, MA)(posted 8090 days ago)