01-20-2012, 04:38 PM
[quote name='Frank' timestamp='1327056275' post='15051']
Hi Wim, may I also ask a theoritical/technical question here. In an ideal case, the optical axis of the lens should be orthogonal to the image censor and pass through the center of the sensor. But in reality errors always exist: if the optical axis of a lens is not perfectly orthogonal to the censor, then there is a tilt; if the optical axis does not pass through the center of the censor, then there is a shift. How large this kind of errors are considered to be within the acceptible limit?
Regards,
Frank
[/quote]
Good question, Frank.
Generally speaking I expect tolerances in this regard to be very, very small, in the order of a few micrometers or less. It has to be, because the effects of this in the sensor plane are really dramatic, as popo actually proved with his post. 15 microns of tilt is too much already <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='
' />. The exact tolerances I don't know, however. And as you know yourself, even with WA lenses, a minute amount of tilt or shift makes quite a difference.
I also expect tolerances in lenses and AF to be quite a bit larger, because those are more difficult to control, due to all the moving parts involved, which means that everything else has to be within as tight as possible tolerances.
Kind regards, Wim
Hi Wim, may I also ask a theoritical/technical question here. In an ideal case, the optical axis of the lens should be orthogonal to the image censor and pass through the center of the sensor. But in reality errors always exist: if the optical axis of a lens is not perfectly orthogonal to the censor, then there is a tilt; if the optical axis does not pass through the center of the censor, then there is a shift. How large this kind of errors are considered to be within the acceptible limit?
Regards,
Frank
[/quote]
Good question, Frank.
Generally speaking I expect tolerances in this regard to be very, very small, in the order of a few micrometers or less. It has to be, because the effects of this in the sensor plane are really dramatic, as popo actually proved with his post. 15 microns of tilt is too much already <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='
' />. The exact tolerances I don't know, however. And as you know yourself, even with WA lenses, a minute amount of tilt or shift makes quite a difference.I also expect tolerances in lenses and AF to be quite a bit larger, because those are more difficult to control, due to all the moving parts involved, which means that everything else has to be within as tight as possible tolerances.
Kind regards, Wim
Gear: Canon EOS R with 3 primes and 2 zooms, 4 EF-R adapters, Canon EOS 5 (analog), 9 Canon EF primes, a lone Canon EF zoom, 2 extenders, 2 converters, tubes; Olympus OM-D 1 Mk II & Pen F with 12 primes, 6 zooms, and 3 Metabones EF-MFT adapters ....
