Andre Y wrote:
Thanks Roger. I appreciate the follow-up on this lens. The dip in the edges would seem to indicate a cover glass issue, but the central contrast has also increased significantly. Do you guys know what mechanism is causing that?
Also have you noticed any changes in lens variation with the added cover glass? About the same, better, worse?
It makes it clear that for such a fast lens even centre performance can be affected by the cover glass. At f/2 you won't see issues but at f/1.4 and with 2mm of cover glass being off there will be an effect.
I have the two otuses (55 and 28mm) and use them on an A7r, non modified, and both seem to surpass the resolving capability of the sensor at any aperture, anywhere on the frame...
This is not science of course and i am aware theses lenses have their own limits and shortcomings, are made to be at their best with such or such cover glass in front of the sensor, but we would need cameras with much more resolving capacity before we can really notice.
" The other factor that makes me not feel so bad -- back then the manufacturers were TOTALLY secretive about cover glass thickness. They've stopped being that way now and actually it was an email from Zeiss suggesting we retest with cover glass that got me to look at it again. The difference is pretty dramatic. "
Hi, could you tell us the Zeiss recommended thickness of cover glass for their Otuses ?
Thanks a lot for all your testing and knowledge sharing.
So the story is that your on vacation in Greece, you buy a load of gin on the way home, sells it back in Sweden and then you buy that car for the profit?
