Unlike Cheryl, don't shoot moving targets. Therefore I generally have the time to compose fully on the ground glass and I do this every time I release the shutter. Like Francisco said in the other thread about this, when I shoot 8x10 they are contacts and this leaves very little wiggle room for cropping and still having an 8x10 contact print. Some may say they do it for a "purity of vision". I know guys that full frame every format. 35mm to 7x17. It is a good excersise for people to learn to see in their chosen format.