I have a Polaroid 6x6 projector. They were used as a sales tool for one of their products but can no longer remember which, possibly their Polarvision. I mount my 645 transparencies in a frame 2 1/4 x 2 1/4 sized mount cut for 645. Most of my 645 slides are b&w and if you think color can be amazing, try some mf b&w slides - truly awesome. Sadly, the photo club I belonged to banned me from the slide competitions as everyone knew whose slides they were.