Justin Berman Offline Buy and Sell: On
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So why no AF from Zeiss? | |
Andre Labonte wrote:
Chris Langer wrote:
I do not know much about AF and lens formula's but I am sure if you put AF or other modern new features, the glass will have to change its formula which could cause less quality from the Zeiss. Just a thought.
Chris
Not really. It's a matter of setting a motor to turn the focus ring instead of your hand. AFS is a little different, but not much.
Let's be clear, a given optical formula is present in the zeiss line. The optical formula relies on the fact that the user can supply a large amount of turning power relative to the weight of the optics, thus the optics can be kept tight, heavy and extremely high quality. To get the same movements for AF function, you either have to have a super slow focusing AF (to move the same heavy elements) or you have to change the optical formula to allow for an AF motor to move them. In point of fact, AF lenses are further complicated by the fact that the elements that move are restricted to provide responsive AF functionality.
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