I recently purchased a Mamiya M645 1000s with a Prism S finder and an 80mm f/2.8 lens. So far, I really like the combination, and I'm having fun using the camera. I do some on location amatuer model shoots and such, and I really like to play around with strobe lighting. I haven't done it much with this camera because of the low sync speed. I understand that a lot of photographers like to use the leaf shutter lenses so they can use fill flash in brighter sunlight, at higher shutter speeds. Are there other useful functions of the leaf shutter lenses? I was thinking it might be an advantage using a strobe indoors. A lot of times, I get unwanted spill on the background in a smaller room. If I used a leaf shutter lens, perhaps I can use a strobe (unmodified...bare bulb, etc) with a shutter speed of 1/500, an light the person, but reduce most, if not all of the light spill? Does this make sense? Sometimes, I'm in a bright walled room, and I don't want the background to show up. I typically use my flashes off camera, but without a lot of modifiers, it's at times difficult to control spill in a smaller room, with light colored walls. Yes...I know, I need a studio So, based on some of the things mentioned above, is a leaf shutter lens worth the cost for me?