I know this is a stupid question but... I have a Pentax 67 which I just recently purchased in the past few months and love. However, I really have fallen for the 6x6 (square) particularly for abstracts and still lifes. The crux is that I compose images in the frame of my camera and I have a hard time trying to visualize a square image out of a rectangular frame. I wish there was a type of mask I could use. I have a TLR (autocord) which is excellent, but I would like to be able to just use one camera instead of carrying around two. Carrying the pentax is like carrying two cameras anyway Does any veterns have any tips on how to visualize a square image in a rectangle frame when one is out in the field or is this something that is left for the darkroom, after the fact?