I didn't know Polaroid darkslides were different than others for the RB's but I'm glad to know that little tidbit. Anyway, I was thinking that perhaps if might be better to have a 4X5 field camera for those Polaroid shots. That way you are giving them a bigger picture, and I believe there would not be the dark border cut off. You would have to load them seperately I think, (I'm not familiar with 4X5's). A used Toyo or something might be another option. I will take back the statement I made about the backs being a hassle to remove from the RB's. Yes, it is a quick process, but you then have a back to take care of. If you have an assistant, that person can be setting up the 4X5 while you are shooting something else. Just a thought, may not be a good one though.