08-11-2010, 01:28 AM
[quote name='Klaus' timestamp='1281457195' post='1648']
e.g. the Voigtländer 15mm lens is supposed to be a very decent performer when used on the a Leica M6 (film) yet it performs poor on the M9 so there is a sensor dependency somewhere.
[/quote]
Thanks for your reply. I have no doubt that the M8 and M9 sensors have trouble (due to their outdated designs) when dealing with light hitting from high angles of incidence, especially on their larger sensor areas. I'm still puzzled how this issue could be there on the more modern and much smaller mFT sensors, especially when there's no sign of this happening when looking at the amounts of vignetting.
As for the Voigtländer 15mm issue on digital M... again I think it's a result of the M sensors being bad. For example, here's the same lens (but in SL mount) [url="http://www.16-9.net/lens_tests/15mm_test1.html"]hack mounted[/url] on 5D MkI and compared against the Sigma 12-24:
http://www.16-9.net/lens_tests/15mm_test1b.html
On the more modern and smaller mFT and Nex APS-C sensors, I expect it to perform even better.
[quote name='wim' timestamp='1281473125' post='1652']
Yes, that, and the relative thickness of film, which covers up a lot of field curvature problems already, and the fact that silicon also has optical properties, unlike the emulsion used in film. And at certain angles of incidence this really comes into play, especially because about half of the light is reflected back as well (with film that is only about 2-3%).
[/quote]
Interesting stuff, Wim... thanks for adding. Like I said to Klaus, I'm still puzzled how none of these are reflected in the vignetting <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/laugh.gif' class='bbc_emoticon' alt='B)' />
GTW
e.g. the Voigtländer 15mm lens is supposed to be a very decent performer when used on the a Leica M6 (film) yet it performs poor on the M9 so there is a sensor dependency somewhere.
[/quote]
Thanks for your reply. I have no doubt that the M8 and M9 sensors have trouble (due to their outdated designs) when dealing with light hitting from high angles of incidence, especially on their larger sensor areas. I'm still puzzled how this issue could be there on the more modern and much smaller mFT sensors, especially when there's no sign of this happening when looking at the amounts of vignetting.
As for the Voigtländer 15mm issue on digital M... again I think it's a result of the M sensors being bad. For example, here's the same lens (but in SL mount) [url="http://www.16-9.net/lens_tests/15mm_test1.html"]hack mounted[/url] on 5D MkI and compared against the Sigma 12-24:
http://www.16-9.net/lens_tests/15mm_test1b.html
On the more modern and smaller mFT and Nex APS-C sensors, I expect it to perform even better.
[quote name='wim' timestamp='1281473125' post='1652']
Yes, that, and the relative thickness of film, which covers up a lot of field curvature problems already, and the fact that silicon also has optical properties, unlike the emulsion used in film. And at certain angles of incidence this really comes into play, especially because about half of the light is reflected back as well (with film that is only about 2-3%).
[/quote]
Interesting stuff, Wim... thanks for adding. Like I said to Klaus, I'm still puzzled how none of these are reflected in the vignetting <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/laugh.gif' class='bbc_emoticon' alt='B)' />
GTW