12-01-2010, 10:53 PM
[quote name='Sylvain' timestamp='1291197218' post='4633']
Now one could argue about the relevance of such findings IRL, but then, one could discuss the relevance of the slimmest form of pixel peeping. Who sets the limit?
[/quote]
Yes... the light loss at the corners is real but I just have serious doubts about their claims... especially since their methodology needs to be very carefully constructed to measure such things but they're so secretive about it.
Just for the record, I too think DxO is one of the better sites out there for sensor testing. For example the results from a test that I did and what DxO published on the same topic were similar (and both were published almost simultaneously):
November 8, 2008: http://www.flickr.com/photos/genotypewriter/3012247230
November 16, 2008: http://www.dxomark.com/index.php/en/Our-publications/DxOMark-Insights/More-pixels-offset-noise!/Real-life-comparisons
But I don't think they're doing everything the right way.
[quote name='Brightcolours' timestamp='1291210980' post='4652']
Attach the prime, wide open, to the camera (Canon EOS DSLR). Make a photo. Camera is aware of the lens, and the used aperture.
Press the lens unlock button and turn the lens a bit. Now the electrical contacts are not used anymore. Camera sees NO lens, and has no idea of used aperture. Make a photo.
Compare both photos. My guess: Both photos will be exposed exactly the same.
[/quote]
This is what I was going to do... except I was thinking about putting something like a thin film over the contacts. Just haven't had time to do it.
GTW
Now one could argue about the relevance of such findings IRL, but then, one could discuss the relevance of the slimmest form of pixel peeping. Who sets the limit?
[/quote]
Yes... the light loss at the corners is real but I just have serious doubts about their claims... especially since their methodology needs to be very carefully constructed to measure such things but they're so secretive about it.
Just for the record, I too think DxO is one of the better sites out there for sensor testing. For example the results from a test that I did and what DxO published on the same topic were similar (and both were published almost simultaneously):
November 8, 2008: http://www.flickr.com/photos/genotypewriter/3012247230
November 16, 2008: http://www.dxomark.com/index.php/en/Our-publications/DxOMark-Insights/More-pixels-offset-noise!/Real-life-comparisons
But I don't think they're doing everything the right way.
[quote name='Brightcolours' timestamp='1291210980' post='4652']
Attach the prime, wide open, to the camera (Canon EOS DSLR). Make a photo. Camera is aware of the lens, and the used aperture.
Press the lens unlock button and turn the lens a bit. Now the electrical contacts are not used anymore. Camera sees NO lens, and has no idea of used aperture. Make a photo.
Compare both photos. My guess: Both photos will be exposed exactly the same.
[/quote]
This is what I was going to do... except I was thinking about putting something like a thin film over the contacts. Just haven't had time to do it.
GTW