I'm in acordance with Ellis and John. I'm a novice and last weekend I tasted a 72XL with my Canham. This lens has a big image circle, much bigger than the circle formed with the corners of the format in extreme movements. I draw in a paper the circles of the 72XL and the 75 "normal", and the circle that the corners of the format "draw" in extreme movements. The 75mm exceed the capacity of the camera in rise/fall, and is moreless the same in lateral shifts. Focusing to a near subject, the circle grows, and the also capacity. The capacity of movements with the camera focused to infinity are limited by the bellows compression (to one inch moreless in the DLC45) when you use this wide angle lenses. That's the reason because I think that a 75mm works better with field cameras (without a bag bellows, of course). The 72XL is a monster. I don't recommend it for my camera. Another topic is the rear element. If the front of the bellows isn't wide enough, it can limit too the movement. I disagree partially with Ellis, when he said that you can use a 58mm with no problems with the Canham, because the same reason. You can use it with a limited capacity. The compression of the bellows would be bigger with this lens, unless you choose a recessed board like he does (I understand now why he has the Linhof front). He is one of the users that convince me with the Canham. I'm so happy with the DLC. Not yaw free is not a problem to me.