Hi, > I saw a picture, of a lens by Leica, and I > don't know if this is common at all, but it had the ring at the top.
all the Leica M lenses are like that. The Leica R lenses have the aperture by the body, like Pentax. Olympus SLR lenses have the aperture ring at the far end of the lens, too. With some of the Leica M lenses it can be slightly inconvenient to use when you have a hood attached, but on these lenses the aperture ring has a couple of tabs. I'm thinking in particular here of the Summilux-M 35mm f/1.4, non-aspherical version, which is a really tiny little lens and probably no good at all for people with chunky fingers. Incidentally, for anybody interested in Leica, the new edition of the Leica Pocket Book includes MTF graphs for *all* the lenses - not just the current ones - as well as an interpretation of the graphs for each lens, and a good explanation of MTF. --- Bob
