Henning Wulff wrote: >> Well, why? Even when cropping a D1s image to D60 size (1/1.6 factor), >> it will still have slightly more pixels than a full D60 frame >> >> Per > > > Not quite correct :-) > > The 1.6 factor is linear, but the pixel count describes an area. So you > have to square 1.6, which gives you a factor of 2.56. This, into 11.1Mp, > gives you 4.35Mp, while the D60 has 6.3 or so.
Of course you�re right! Stupid of me... > > The other thing that hasn't been mentioned is that film has a much finer > basic unit: the silver halide grain than digital, which has an active > electronic element. For the foreseeable future, we're not likely able to > make a transistor with wires smaller than a silver halide crystal. Then > comes the fact that to make a 'unit' of colour information we need 4 > active electronic elements, with conductors (one red, one blue, and two > green in the usual bayer patter). An 11.1Mp sensor gives use 2.775Mp of > true information which with some elegant interpolation algorithms gives > us 11.1Mp of output again. We're not in film territory by a long shot. > Well, here is a complication: a CCD (CMOS) cell has a more or less continuous scale of excitation, which the A/D converter represents by, say, a 12 bit binary number (in RAW) for the intensity there. A single silver halide grain (not to be confused with silver grains after development) is excited or it is not, giving one bit of intensiy information. So, paradoxically, film is a digital device, while sensor cells are analog... The continuous tone scale in film is the result of many grains cooperating to a greater or smaller degree, in proportion with the photon density received. So any comparison between film and sensors is far more complicated than it would seem. Agreed, we�re not in film territory yet (look at grass or foliage in a MF shot beside a digital one), but it is not entirely clear how far off we are... Anyway, we seem to have digressed seriously from the initial question :-) Per * **** ******* *********************************************************** * For list instructions, including unsubscribe, see: * http://www.a1.nl/phomepag/markerink/eos_list.htm ***********************************************************
