Ripolini wrote:
I'd say, "like Voigtlander claims".
I know, we all know, that Voigt M-versions don't perform as well as Z-mount versions on Nikon bodies due to corner degradation (visible even when adapting the VM 90/2 Apo). However, apart from what Cosina states in its brochures, the company does not specify what "optical changes" have been made to the Z- and E-mount versions. The only transparent information is available for the 50/2 AL, whose E- and Z-mount versions have a visibly different optical scheme. We even don't know if Z- and E-version share the same "optical formula" or they differ someway according to the different sensor stack thickness of Sony and Nikon MILCs.
Consequently, I have a number of doubts and questions that no one can answer without venturing into speculation based on personal impressions – and therefore nothing technically sound:
- why Cosina changed the optical scheme of the VM 50/2 AL when they introduced the E-mount version?
- does the Z-mount version of the 50/2 AL differ for the E-mount version? (same question applies to other Voigtlander lenses available in both E- and Z-mount)
- when we talk about ‘optical changes’, what exactly do we mean?
- does Cosina use glass elements with a different composition and/or curvature?
- does Cosina alter the distances between the various elements? or does it simply adjust the distance between the rear element and the sensor to account for the sensor stack filter thickness? ...Show more →
What we do know, however, from a number of reviews that Fred has done on this site and that the team has done on philipreeve.net is that specific mount version from Voigtlander perform better on those mounts than M mount versions. This repeated finding does suggest that Voigtlander changes something. We have some idea what they change with the 50 f/2 AL--the glass types are different--but in almost all other cases we don't know what they change and we have less information about whether lets say E mount version and Z mount version differ. Some have claimed to have tested E mount versions on Z mount cameras and say the Z mount versions do better, but I can't recall seeing any clear evidence of that in the same way that I have seen lots of clear evidence that E and Z mount lenses perform better on the camera for which they were made than M mount versions of the lens.
Steve Spencer wrote:
What we do know, however, from a number of reviews that Fred has done on this site and that the team has done on philipreeve.net is that specific mount version from Voigtlander perform better on those mounts than M mount versions.
...
I have seen lots of clear evidence that E and Z mount lenses perform better on the camera for which they were made than M mount versions of the lens.
Right, it's what I wrote using different words. Probably I wasn't clear enough.
Steve Spencer wrote:
This repeated finding does suggest that Voigtlander changes something.
Yes, but nobody knows what is technically necessary to tweak the lens for a specific mount.
Is it such an important trade secret that it mustn't be revealed to anyone—otherwise Cosina will go out of business—or is it something so trivial that you're almost ashamed to say it?
Jun 17, 2026 at 10:29 AM
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Ripolini wrote:
Right, it's what I wrote using different words. Probably I wasn't clear enough.
Yes, but nobody knows what is technically necessary to tweak the lens for a specific mount.
Is it such an important trade secret that it mustn't be revealed to anyone—otherwise Cosina will go out of business—or is it something so trivial that you're almost ashamed to say it?
I don't know enough to know the answer to that last question. I also wanted to make one correction from what you asked above. The Sony E mount version of the 50 f/2 APO was actually introduced a little over a year before the Leica M mount version of this lens (December, 2019 for the E mount version and January, 2021 for the M mount version). So, they presumably changed the E mount version when they made the M mount version. We could speculate about why they did so, but the change given the different introduction dates was very likely in that direction.
paulleica wrote:
What’s more, the focus ring is far too stiff, which exacerbates the problem. The peculiar mechanism for the unusual depth-of-field indicator is quite an interesting feature, but it serves no practical purpose, as it appears to be the reason for the stiffness.
Odd, my Simera 50 has a rather loose feeling focus ring. My suspicion is that Thypoch's quality control is not quite up there compared to other manufacturers (at least not yet). That's probably part of how they are (relatively) affordable.
At wide-open aperture, this lens is prone to really severe purple chromatic aberrations. That didn’t exactly win me over either.
My copy doesn't seem that bad. Yes, it's there, but it's easy enough to correct. This plus the focusing ring comment makes me wonder if you just had a bad copy.
