Proof of concept to fix Olympus B300 1.7 X in mount/support bracket for D7 so that the D7 camera can be quickly mounted or dis-mounted from the support bracket without havig to screw/unscrew a 49-55mm stepup ring between the camera lens and the B300.

I just use a 62-55mm Bowers step-down ring that I purchased from 2filters.com and this stays on the B300 and captures the tele-converter in the mount ring. Whenever I want to use the B300, I just mount the D7 into the support bracket and zoom the lens out to max and carefull fit the lens into the 62mm opening of the set-down ring and I am ready for action. Additional advantage is that this gets the D7 lens as close to the B300 as possible. I believe I don't have much vignetting if at all. I do see some corner fall off though.

I plan to have a machine shop mill a little inside diameter out of the 62mm set-down ring so I can add some black photograic masking or electricians tape so the existing threads will not scratch the outside of the camera lens.