Kostas asked what lens-internal focus motors add, besides weight. COST
Just kidding! Sort of. Lens-internal focus motors, at least the ultrasonic kind, are in my experience quieter to focus and MUCH faster than depending on camera-internal focus motors, especially for larger lenses. Nikon SWM and Canon USM also allow instant manual focus override without any silly clutching mechanism or mode switch. No mechanical gears to fight since it's all ultrasonic. This means you can leave the lens and camera set to AF and still work MF if you want to. As to those ME Super buttons: Don't most folk have their shutter speed dial on "A" or "P" anyway? ;-) Realistically, I can turn a shutter speed dial with my fingers just the way you can push the buttons, without taking my eye from the finder. I can also see by looking down at the top of my camera where the shutter speed is set, which the ME Super couldn't tell me (but subsequent cameras can, of course). Yes, most modern cameras follow the ME Super in control layout by using electronic buttons and dials. In some cases, it's a bad idea. Nikon guys are still bitching about the "G" series lenses without aperture rings, like the Pentax FA-J as I recall. This makes them impossible to use with older cameras. It also means that you can't control the aperture with your LEFT hand, which is down there focusing or supporting the lens anyway, but have to take your finger off the trigger to work some wretched wheely thing. Yes, some cameras have a thumbwheel or switcheable setup, but in general it makes for a high right hand workload and nothing to do with the left hand but run the zoom ring. Maybe some folks can use a finger other than their trigger finger to manipulate controls, but I can't. My thumb already has stuff to do with the AF selector button or AF start button, and the rest of my hand is holding the 500 pound camera steady. Now there ARE arguments for the newer "user interface". I LOVE having half-step apertures and shutter speeds availible and that would be hard to do with a true mechanical analog interface. I can't see that it would be so hard to put an electronic "aperture ring" somewhere down where the left hand used to find the old mechanical one (or for Olympus guys, the shutter speed ring!). DJE
