Steve Spencer wrote:
I suspect, but have no evidence that Thypoch is not adjusting the optical formula for the sensor stack thickness like Voigtlander does...
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?
paulleica wrote:
The German proverb ‘you get what you pay for’ certainly applies to this product. Fortunately, you can return products ordered online.
An economist once said: if you pay too much for something, you’ve been robbed of a bit of money; if you pay too little, you’ve been robbed of it all
