02-26-2017, 09:04 AM
Some change the direction of focus and zoom rings to match the original manufacturer, some don't. IIRC, Zeiss does it but Sigma keeps it as is. So some of them at least have some of the internals changed from mount to mount. Not the optics though.
Most of them add the aperture ring on Nikon versions. Again, Zeiss does it but Sigma doesn't.
Since Sony A-Mount doesn't support IS in lens, some manufacturers simply remove the IS by fixing the stabilizing group of lenses. Optics are still the same.
Tamron used to have Adapt-all series or named something similar where you could have change the lens mount to adapt the lens to multiple mounts. What Sigma does not via a paid service, 30 years ago. And it was just changing the back of the lens in a few seconds.
Voigtlander tweaks the optical formula slightly in their E-Mount lenses compared to M mount lenses.
Most of them add the aperture ring on Nikon versions. Again, Zeiss does it but Sigma doesn't.
Since Sony A-Mount doesn't support IS in lens, some manufacturers simply remove the IS by fixing the stabilizing group of lenses. Optics are still the same.
Tamron used to have Adapt-all series or named something similar where you could have change the lens mount to adapt the lens to multiple mounts. What Sigma does not via a paid service, 30 years ago. And it was just changing the back of the lens in a few seconds.
Voigtlander tweaks the optical formula slightly in their E-Mount lenses compared to M mount lenses.