M645 to SONY-E adapter

As I looked for Mamiya 645 to SONY-E mount adapter in the Web site, I didn't find it out in the reliable seller except strange PRC site. My conclusion was that I was cornered in all directions, fabricate it by myself.

Canon EF to SONY-E mount adapter that did not work well when Canon Auto focusing function was tested, just makes heat inside and thrown away for long time. I happened to realize utilizing this trash part for useful device!

Comparison on flange back between 645 and SONY-E, 64.0 mm and 18 mm, 46 mm clearance must be fulfilled by some method? Careful measurement of the compensating part led me to the smart conclusion.

Mamiya genuine part, Auto-Ext Ring No.2 was applicable for the purpose, on the way 0.3 mm grinding adjustment was required to establish infinity focusing. As the lens barrel length adjustment for the infinity position differs, careful adjustment was required.

Avoiding light axis bending, a stout supporting rail is indispensable in actual shooting scenery especially, small diameter flange is invited like SONY E mount, I make it a rule to insert a triangular small wood piece at adequate position. Bayonet spring and lens barrel moving parts like helicoid and cam constructions are the climinal of distortion.

As Mamiya Zoom has some mist covering and colony of mold on lenses inside, I would like to have so transparent image after cleaning.
I want to believe in that the dull pic quality is not brought by its innate performance but by acquired bad conditions written above.

To tell the truth, I remembered 30 years ago that I was disappointed by the performance of C 80mm/f1.9, just I pray not to have the same result at all. The standard control for comparison now is Minolta MD Zoom 100~200mm/f5.6?