12-21-2011, 04:53 PM
[quote name='TheChris' timestamp='1324463527' post='13968']
Thanks Wim for the explanation! I observed differences in the way areas outside the DOF are rendered on film on many of my shots. I contributed this to the way sensors work, bayer pattern and sharpness algorithms came to my mind. What you describe here makes sense and I have seen the result in form of a difference in response to MFT test patterns in another article that was well written.
Subjectively, I can confirm that the out of focus areas of my AF-S 50mm f/1.4 do look nicer on film than on my Fuji S5 despite being not bad on the S5 anyway. But I cannot make a direct comparison as the FOV and DOF would be different (35mm film vs. APS-C sensor).
If it is of interest to some of you, I can probably put some samples of f/1.4 shots online that where taken on film using the AF-S 50mm f/1.4 so you can judge yourself.
Christian
EDIT: Oh, and Markus - thanks for testing the Noctilux! Very, very interesting - somehow nice to know that even the most expensive 50mm would not be necessarily the best choice for me personally. Don't like the way it renders the scene at all.
[/quote]
Hi Christian,
I did find that once one gets to higher resolution sensors, the images start to look more like images from film again, basically, I reckon, because lens quality and sensor resolution combine for a more gradual trailing off of the image quality, based on the lens formula. This probably because sensor resolution creeps a little closer to lens resolution, and the AA filter has less of a topping off effect as a result.
From what I have noticed, this is the case with APS-C sensors from about 14-15 MP, and with FF sensors probably about 16-17 MP. Relatively speaking, DoF still comes in quickly, but the overal curve starts looking more like a film curve, even if compressed more than a film curve. The AA-filter essentially has less of a topping effect, so to speak, as with lower MP sensors. Topping off at 40 lp/mm affects a wider range over the DoF zone than topping off at, e.g., 75 lp/mm.
You can also have a look at MTF-charts here to see things like that happening: with lower MP sensors the MTF-charts are generally flatter than with higher MP MTF charts. Edges and corners are generally very much closer in the former than in the latter, and going from APS-C to FF this is even more pronounced. Check, f.e., the Canon 85L on different bodies. Of course, on APS-C bodies FF lenses do benefit as well from using the best part of the glass, but that makes this effect even stronger overall <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='
' />.
Kind regards, Wim
Thanks Wim for the explanation! I observed differences in the way areas outside the DOF are rendered on film on many of my shots. I contributed this to the way sensors work, bayer pattern and sharpness algorithms came to my mind. What you describe here makes sense and I have seen the result in form of a difference in response to MFT test patterns in another article that was well written.
Subjectively, I can confirm that the out of focus areas of my AF-S 50mm f/1.4 do look nicer on film than on my Fuji S5 despite being not bad on the S5 anyway. But I cannot make a direct comparison as the FOV and DOF would be different (35mm film vs. APS-C sensor).
If it is of interest to some of you, I can probably put some samples of f/1.4 shots online that where taken on film using the AF-S 50mm f/1.4 so you can judge yourself.
Christian
EDIT: Oh, and Markus - thanks for testing the Noctilux! Very, very interesting - somehow nice to know that even the most expensive 50mm would not be necessarily the best choice for me personally. Don't like the way it renders the scene at all.
[/quote]
Hi Christian,
I did find that once one gets to higher resolution sensors, the images start to look more like images from film again, basically, I reckon, because lens quality and sensor resolution combine for a more gradual trailing off of the image quality, based on the lens formula. This probably because sensor resolution creeps a little closer to lens resolution, and the AA filter has less of a topping off effect as a result.
From what I have noticed, this is the case with APS-C sensors from about 14-15 MP, and with FF sensors probably about 16-17 MP. Relatively speaking, DoF still comes in quickly, but the overal curve starts looking more like a film curve, even if compressed more than a film curve. The AA-filter essentially has less of a topping effect, so to speak, as with lower MP sensors. Topping off at 40 lp/mm affects a wider range over the DoF zone than topping off at, e.g., 75 lp/mm.
You can also have a look at MTF-charts here to see things like that happening: with lower MP sensors the MTF-charts are generally flatter than with higher MP MTF charts. Edges and corners are generally very much closer in the former than in the latter, and going from APS-C to FF this is even more pronounced. Check, f.e., the Canon 85L on different bodies. Of course, on APS-C bodies FF lenses do benefit as well from using the best part of the glass, but that makes this effect even stronger overall <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='
' />.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 ....