12-19-2011, 10:44 PM
[quote name='joachim' timestamp='1324328914' post='13928']
What else would one want if not Ektachrome. Don't tell me Velvia <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/tongue.gif' class='bbc_emoticon' alt='
' />
On a serious note, I could easily imagine that sensors mess up the bokeh of a lens. The lensing in the sensor could easily modify the pattern. After all they are just another few lens elements to add to the optical train.
[/quote]
I wouldn't think so - these are not image forming elements, only light gathering elements, similar in a way to a condensor in an enlarger, be it the other way around <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='
' />.
They even prevent some of the CA and vignetting you see with sensors who do not have them, especially with (U)WA lenses, and worst in non-retrofocus (U)WA lenses as used with e.g., rangefinders <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='' />..
There is an interesting difference between film and sensors, however, when it comes to the image forming department. Film emulsion has a thickness of approximately 0.2 mm, while sensors have a thickness of 0.000 mm as far as the recording medium is concerned (zero thickness). With film this adds significantly to DoF, but also to a more gradual transition from unsharp to sharp in the DoF zone. Close to the point focused on, with digital sharpness ramps up very quickly, abruptly one could say, whereas with film this is more gradual, more gently.
0.2 mm does't sound like a lot, but considering the CoC for DoF calculations on FF is 0.03 mm, and for APS-C less than 0.02 mm (0.0186 for Canon, 0.0196 for Nikon), this is a rather significant amount. This doesn't necessarily mean that film really has a lot more DoF, because sharpness is a matter of a complex formula and multiplication factors. However, it does mean that film has a little more DoF at a lesser sharpness than a sensor, and also has less maximum sharpness right at its peak than a sensor has. This also means, BTW, that film is less sensitive to focusing errors than a sensor.
Kind regards, Wim
What else would one want if not Ektachrome. Don't tell me Velvia <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/tongue.gif' class='bbc_emoticon' alt='
' />On a serious note, I could easily imagine that sensors mess up the bokeh of a lens. The lensing in the sensor could easily modify the pattern. After all they are just another few lens elements to add to the optical train.
[/quote]
I wouldn't think so - these are not image forming elements, only light gathering elements, similar in a way to a condensor in an enlarger, be it the other way around <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='
' />.They even prevent some of the CA and vignetting you see with sensors who do not have them, especially with (U)WA lenses, and worst in non-retrofocus (U)WA lenses as used with e.g., rangefinders <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='
' />..There is an interesting difference between film and sensors, however, when it comes to the image forming department. Film emulsion has a thickness of approximately 0.2 mm, while sensors have a thickness of 0.000 mm as far as the recording medium is concerned (zero thickness). With film this adds significantly to DoF, but also to a more gradual transition from unsharp to sharp in the DoF zone. Close to the point focused on, with digital sharpness ramps up very quickly, abruptly one could say, whereas with film this is more gradual, more gently.
0.2 mm does't sound like a lot, but considering the CoC for DoF calculations on FF is 0.03 mm, and for APS-C less than 0.02 mm (0.0186 for Canon, 0.0196 for Nikon), this is a rather significant amount. This doesn't necessarily mean that film really has a lot more DoF, because sharpness is a matter of a complex formula and multiplication factors. However, it does mean that film has a little more DoF at a lesser sharpness than a sensor, and also has less maximum sharpness right at its peak than a sensor has. This also means, BTW, that film is less sensitive to focusing errors than a sensor.
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 ....