Well I got my M42 adapters from poland the other day and pulled my old Minolta lens apart. There are eight screws through the flange and into a spacer. I pulled the flange off, turned the diameter of the adapter to fit, and machined counter sunk holes in the adapter. I put it together, mounted it on the camera and thanks to Klaus' instructions on setting up old lenses I took a couple of shots in the house.
The shots looked good exposure wise and the autofocus light came on when it should. Now I have to fix infinity focus. The rokkor was set at[focal plane distance?] 43.5mm from what I have read and the sigma is 44mm. The original flange was 1mm thick and the adapter 1.5mm. So I will shave .5mm off the adapter and .5mm off the spacer and I think it will be done.
I will send photos and a write up when it is done..............Tom C
The shots looked good exposure wise and the autofocus light came on when it should. Now I have to fix infinity focus. The rokkor was set at[focal plane distance?] 43.5mm from what I have read and the sigma is 44mm. The original flange was 1mm thick and the adapter 1.5mm. So I will shave .5mm off the adapter and .5mm off the spacer and I think it will be done.
I will send photos and a write up when it is done..............Tom C