07-21-2010, 01:47 PM
[quote name='Yakim' date='21 July 2010 - 02:10 PM' timestamp='1279714230' post='1198']
Why? The adapter mechanically closes the aperture.
[/quote]
Actually, there is no way to really control the closing of the aperture, unless you have a mechanical coupling that knows exactly how far to go. That is one of the difficulties to overcome, because if the camera it is mounted on doesn't support it, it really takes a lot of effort to try and figure this out and make it work reliably.
Next, a G-EOS adapter for Canon EF lenses is a lot harder to make, considering the little amount of space that is available to control the aperture itn the first place. Making it work reliably, controllably, and so that it will keep working with time (IOW, a mechanism that isn't flimsy), is even harder. To be very honest, the only reason to own a G-EOS adapter, apart from testing Nikon automatic aperture only lenses on a Canon body, is the Nikkor 14-24, as Canon doesn't manuafacture a lens equivalent (yet). This means the market is rather small for this, unlike for normal N-EOS adapters, with a wealth of lenses that stil have an aperture ring, for the MF enthousiasts amongst us. Note that a G-EOS adapter only has 3 settings due to the limited space and short distance over which the Nikon aperture lever travels, namely wide open, F/8, and completely closed.
I did own a 14-24 with G-EOS adapter. It is a very, very good lens, but rather cumbersome to work with in all manual mode, and having to close the aperture based on changing shutter times for optimal effect (going to F/8 first when metering, and changing it slowly until the shutter times indicate that the aperture of preference for a particular shot is reached). After I finally got a TS-E 17L I did eventully sell it as a result, because it didn't get any use anymore. The latter is even better anyway <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='B)' />.
Kind regards, Wim
Why? The adapter mechanically closes the aperture.
[/quote]
Actually, there is no way to really control the closing of the aperture, unless you have a mechanical coupling that knows exactly how far to go. That is one of the difficulties to overcome, because if the camera it is mounted on doesn't support it, it really takes a lot of effort to try and figure this out and make it work reliably.
Next, a G-EOS adapter for Canon EF lenses is a lot harder to make, considering the little amount of space that is available to control the aperture itn the first place. Making it work reliably, controllably, and so that it will keep working with time (IOW, a mechanism that isn't flimsy), is even harder. To be very honest, the only reason to own a G-EOS adapter, apart from testing Nikon automatic aperture only lenses on a Canon body, is the Nikkor 14-24, as Canon doesn't manuafacture a lens equivalent (yet). This means the market is rather small for this, unlike for normal N-EOS adapters, with a wealth of lenses that stil have an aperture ring, for the MF enthousiasts amongst us. Note that a G-EOS adapter only has 3 settings due to the limited space and short distance over which the Nikon aperture lever travels, namely wide open, F/8, and completely closed.
I did own a 14-24 with G-EOS adapter. It is a very, very good lens, but rather cumbersome to work with in all manual mode, and having to close the aperture based on changing shutter times for optimal effect (going to F/8 first when metering, and changing it slowly until the shutter times indicate that the aperture of preference for a particular shot is reached). After I finally got a TS-E 17L I did eventully sell it as a result, because it didn't get any use anymore. The latter is even better anyway <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='B)' />.
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 ....
