Archived posting to the Leica Users Group, 2008/12/08
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]On Dec 8, 2008, at 12:58 PM, Bob W wrote: >>> >>> I should think there are plenty of reasons why. My experience of >>> some of the >>> Zeiss lenses on film and digital supports this. Although I never >>> particularly compared bokeh >> >> that is very interesting, though I am talking about bokeh per >> se...do >> you have any examples? what reasons explain it? >> >> > > there are several important differences between film and digital > sensors, > including these: > > 1. the distribution of grain particles on film is random, whereas > sensors > are regular > 2. the angle of the light receptors on a digital sensor influences the > amount of light hitting the sensor, and differs across the chip, > whereas the > notion of grain angle does not exist > 3. film and digital sensors respond differently to UV and IR, and > presumably > also to different parts of the visible spectrum > 4. digital sensors don't react as well as film to chromatic > aberrations - > older lenses were designed for film tolerances, not digital > 5. colour and luminance noise are inherent with digital, but not > with film > (which has its own imperfections of course) > 6. Blooming - or whatever its chemical analogue is - is not present > in film > (as far as I know). Different sensors have different ways of > draining the > excess charge. > > I'm not an optical or sensor scientist, so my knowledge of these > things is > rudimentary to say the least, but each of these accounts for > differences > between film and digital responses to light and colour. I see no great > reason for most of them why they should be different for in and out > of focus > areas (although some of the differences are edge-related, so > presumably less > noticeable in oof areas). I'm not a sensor /physicist guy myself, but you really snowed me... with respect to # one above, surely over the distances involved on the film sensor plane we are talking about, even film must be basically random... as far as the rest, I'll buy it, as I can't tell if it's physics or BS... does anyone have any photos that show a bokeh difference film/digital with the same lens... thanks Bob, Steve > > > Bob > > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information