Not really a question, more a bit of a conundrum to ponder over.

We take our LF camera, say a 5x4 with 180mm lens, and our less-discerning friend Jim takes his 35mm camera with 50mm lens. We both point our cameras at a distan t scene, and both cameras take substantially the same angle-of-view (46 degrees diagonal). Now we both shoot something a bit closer, say, 5 metres distance, and the same thing applies. Our lens extensions are in proportion to their focal le ngths, and we each get a slightly smaller coverage angle of our subject than bef ore, but we both get more-or-less the same image.

Now we decide to do some macro work at 1:1. Both our lenses have been extended b y one full focal length, and again everything is in proportion. But now, the fir st day issue commemorative postage stamp that we're shooting nearly fills Jim's frame from corner to corner, while we're left with, well, a postage stamp size i mage in the middle of the frame.

I know that by definition 1:1 is life size, and it'll take a 5x4 size subject to fill my LF ground glass screen, but both myself and Jim have done everything in proportion, and he's ended up with one angle of view, and I've ended up with a much wider one. Why? I've puzzled over this and can't see where the discrepency creeps in. I think it's a geometrists conspiracy against us Large Format users.