Digital versus Film Scan - Misconceptions?
I have read a lot of comments comparing traditional (35 mm) film scanning against direct digital pictures from a DSLR, D100 included... and a lot of comments disturb me, mainly comparisons like "I can scan 35 mm at 4000 (or more) ppi".
I have experience with high performance scanners, from Crosfield, Hell, and Heidelberg (the successors from Hell). I can scan films at 19000 ppi in a Heidelberg 3900 (it is real, no interpolation), 11000 ppi in a more recent Primescan family, or a "mere" 5080 ppi in a Heidelberg Nexscan family. I used all of them.
1) It is possible to scan at very high resolution 35 mm traditional film;
2) If you are using no sharp and blur you will get significant noise from 2000 ppi from a ISO 100 negative film (sometimes lower), and you will get the same noise from 1300 ppi if you are using ISO 400 negative film (the variation is not so huge if you test different brands);
3) Some people get apparent noise free images at higher resolution, it is due to the poor quality of the sensors of the employed scanners that "blur" the images (please examine your negatives in the microscope, if you have doubts);
4) You can get 0%-70% better results if you are using slide films, and/or very slow films;
5) Summary: the current state-of-art DSLR (like D100) can offer comparable resolution quality to negative films and in some cases slide films too.
BUT theoretically the Bayer mosaic and the algorithm used by the DSLR to "demosaic" it (this is the procedure to convert the RAW data to a workable image file, like interpolation) could be a main issue offering a lower REAL resolution than the expected one, but I cannot find any problems (yet).
Of course we have the latitude subject. I have confirmed that my D100 have a latitude higher than a slide film, but slight lower than a negative print film - and this can be a main issue in some dedicated applications, BUT I am convinced resolution is not the question.
O. Cristo, An amateur photo clicker
O.Cristo - An Amateur Photographer
Opinions of men are almost as various as their faces - so many men so many minds. Franklin