I haven't done a product shoot in ages. But, as an exercise, I decided to pullout the Pentax 645 (which I bought on a whim some years ago and have used only once!) to see if the DOF would let me do a particular task. The task is to basically photograph a brick, at a 45 degree angle, close to the camera, with a 75mm lens. The brick represents a typical small object that I've had to shoot now and then. Usually I'd be shooting chandeliers or tables or lamps. But here and there I've had to shoot statuettes, some of which were long rather than tall. The problem is that I don't think that the 645 can do it. I've attached a photo of the 645's viewfinder so you can see what I'm getting at. The front edge of the brick is at minimum focusing distance, which is 60cm. The rear edge is at about 75cm. Even stopped down to f/22, the DOF wouldn't cover it. So... what would you do? I do have two other lenses, a 45mm and an 80-160. The brick can easily be covered by the 45mm, even at f/16. But I don't want to shoot with this focal length. The zoom doesn't have a useful DOF scale at all, although it does stop down to f/32. This kind of situation is a piece of cake with 35mm, of course. This is not by any means a big problem. Partly because I imagine that I'll be using a digital camera if I get more commercial jobs (not likely but you never know). But, I do want to actually use this gear for something. I don't want to waste it by just shooting road signs and flowers. I actually want to give this thing some work, including casual wildlife subject matter. Yeah, I'm looking at the 300mm... I think I've found a lab that offers the ideal balance of cost, turnaround and scan quality. I don't need to shoot medium format, but I'd certainly like to. It's terrific stuff.