Hello! I had my planar not working well with aperture settings (camera quite often didn't show the right aperture).
I discovered that the screws of one metal piece were not fastened nor I could fasten because of fail in the screw hole... Anyway, I removed this metal piece and the aperture settings became good.
Now, I think that this metal piece that I removed was only adding extra strength to the lens-camera linkage.
Thus I can keep shooting without that piece because it is not affecting image quality. This is what I think, but I want to have an opinion by you experts... is that metal piece still necessary?
I am ignorant on that mount (there are too many mounts...), but by its design it definitely is not for strengthening.
I guess it is indicating lens speed for open-apeture metering.
Think of it.