Zeiss 50 Jahre 85mm f1.2 lens on a Mamiya 645AFD body with a digital back.
From start to finish it is a long story but to cut it short, when I started this project I had no idea if this would work at all and if, to what extent. With the Zeiss being rare and pricey, I certainly didn't want to destroy it in the process! But I had no choice, not trying was not an option. I dismantled the rear portion of the lens to make it slimmer, followed by substantial drilling into the Mamiya body to make room for the lens. I also needed to shave the mirror by maybe 2-3cm and remove a fair number of camera components that were in the way. Having done all that, it was then possible to bolt the lens to the camera from the rear. Finally, I had to adjust the focusing screen so focus would match what I'm seeing in the viewfinder.
Function and limitations: Obviously it is not as pretty or as functional as a native lens. The invasive procedure means:
- the lens is attached to the body permanently
- you cannot stop down the lens.
- there is no infinity focus. Max focusing distance is abut 6m
- in the viewfinder the top quarter or so is blacked out because of the mirror shave
- there is no focus assist light; I'm assuming its because I pulled the electronics out
- metering works but its far from accurate. Best to shoot manual with a light meter or check histogram
- focusing is close to guesswork at the longer distances but is surprisingly manageable closer in. I'm using a Maxwell matte focusing screen. It does help.
- the mirror did get somewhat damaged during the modification and it is somewhat less reflective.
- the image circle covers the whole Aptus22 chip
Image quality (as I see it):
- within the lenses designated image circle everything is pin sharp (its even possible to see moire) with a nice smooth rendering
- the edges rapidly lose sharpness and seem to swirl the image around the center. I actually don't see this as a problem, considering my subject matter its more of a plus.
- there is only a (very) small bit of purple fringing in contrasty light
- bokeh is smooth and wonderful
Photos taken with this available here: Zeiss 85mm f1.2