I will be using this lens (or other of similar focal length) on my Toyo 45A field camera (4X5) and although I know most (if not all) 12" lenses will cover 8X10 I want it for it's telephoto ability. I would definitely want it in a shutter and was looking to stay light rather than get a longer, heavier lens since I will be humping my camera in a backpack around Alaska while hiking. I was also looking at a Schenider Xenar 300mm f5.6 in Copal 3 for the same price. It looks like it isn't super big and I have been reading good reviews about it on the net.