lens wide open best

[MarkP]

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Because Leica M film bodies and Leica M digital bodies don't have different flange distances, as simple as that. The guys at popflash.photo just made this story up.

 

By the way—if there really was a difference of 0.04 mm in the flange distances then a 50 mm lens would miss the intended focus distance of 0.9 m by 9.3 mm, not 2 cm.

 

Thanks.

 

 

Nevertheless, upon emailing Zeiss and discussing this they were more than happy to take the lens back for adjustment. So what did they do to improve it?

 

Mark

[01af]

Nevertheless, upon emailing Zeiss and discussing this they were more than happy to take the lens back for adjustment. So what did they do to improve it?

The C Sonnar 50 mm 1:1.5 ZM has some aperture-related focus shift. Usually it's adjusted for optimal focus at f/2.8 so at wider apertures, it will front-focus slightly; at smaller apertures, back-focus slightly. Upon customer's request, they will re-adjust it so it will focus perfectly at full aperture, back-focus slightly at f/2.8, and back-focus more at smaller apertures. For lens testers and pixel peepers, the re-adjustment may look like an improvement but for actual use the original set-up usually is better.