|Posted: Mon Jul 29, 2019 2:55 am Post subject: KOMURANON-S 50mm f3.5 Round Aperture
|KOMURANON-S 50mm f3.5 making a round aperture.
I read about this lens having a non-round aperture wide open and also wondered if it was factory limited. Well it sort of is, and can be opened just enough to round out the bokeh.
Wide Open at f3.5
Side view with retaining ring and aperture selector cover removed. Aperture stop pin is exposed.
Aperture stop pin removed and rotated past end stop. Wide opener!
Complete lens with front and rear groups.
The job would be to grind away the end stop at the open position (Photo 2) and extend it about 5mm. There won't be an extra indent so it will just have to float in the new open position. In order to perform this modification the rest of the aperture assembly would need to be removed.