Posted 26 July 2011 - 08:33
Well, I haven't got a 7D + Novoflex, but I've just tried mounting the 100/2.8 AME + 2X Apo + R8. I've also got the STA1 on the lens. With this combination, the camera + Extender together are heavy enough to put the STA1 forward of the centre of gravity (which is somewhere around the Extender). So the camera tripod mount is behind the CG whereas the STA1 is in front of the CG. I don't know how the weight of the 7D compares with the R8, but the R8 is a heavy camera.
I wouldn't fancy swinging the combination around on a strap all day. The Leica mounts are strong, but not indestructible. (For example, with a big, heavy lens like the 280/4 APO, Leica specifically caution against using the camera neckstrap, and to use the lens strap.) However, the 100/2.8 plus Extender is not in this league, and the camera strap would be OK for "normal" hanging the camera around your neck, but climbing around and running is something else! With your combination, I suspect that the weak link would be the Canon mount and Novoflex adapter.