One of the first things I noticed about the M6 was how easy it is to mount and dismount lenses. I always thought this was one of the great unheralded virtues of the Leica M cameras. <p> The lens release presses back into the camera, and its right beneath your thumb when you grasp the lens, making removal a one-handed operation. The lenses are small and have a solid base to grasp, instead of a spinning aperture ring. <p> But the thing that really makes it work is the little red index dot on the base of the lens. Simply brilliant. With an SLR (or, ahem, a Contax G) you have to line up a tiny little red mark behind the lens as it disappears into the camera, an awkward operation at best. With the Leica M, you just push the lens into the camera and click - your done. <p> That little red dot is one of the great achievements of modern civilization. I didn't know how fond I was of the little bugger until it disappeared from my 50mm Summicron. <p> I understand its common for these to fall off and get lost. Does anyone know about getting it replaced, or fixing it so it doesn't fall off anymore?