Just recently I had some of the Zeiss ZF lenses I own converted to Canon EOS mount by Duclos Lenses and thought I would share why I did this and the excellent job Duclos did. I only did this on the 3 out of the 5 Zeiss ZF lenses that I own and the reason why I only did 3 was because I needed the 50mm f1.4, 85mm f1.4 and the 100mm f2 rock solid in my Epic. Before I had adaptor rings from Cinevate and they worked okay. Some of the lenses fit better than the others and some were a little loose in the mount. So this was one of the big reasons why I decided to convert the ZFs to Canon mount. Here are some pictures of the lenses converted to the EOS mount.
These lenses have also been Cine-Moded by Duclos which includes the 32-Pitch Focus Gear, Aperture De-Click, 80mm Front Ring and 80mm Front Cap.
Just to compare lens mounts heres the converted lens on the left and the Canon EOS mount from the 16-35mm on the right
The Canon mounts also have a nice red dot to let you know where to line the lens up in the camera mount.
When I had Duclos put the Canon mounts on I had them re-click the lenses only because I never find myself ever having to do an iris rack and would rather know that once I set the iris its going to stay exactly where I set it. The price for the Cine-Mod is $250 per lens and the price for the Canon mount conversion is $160. Of course you could always buy the ZE series Zeiss lenses that come with the Canon mount. But if your going to take a hit on selling a used Ziess ZF lens to buy a ZE mount then the cost of doing the conversion isn't so bad. Plus I like having the manual iris ring on my lenses.