Print Tonality was Re: [Digital BW] Thoughts about Imaging
2002-04-04 by Martin Wesley
(snip) > > Number isn't a good word for this concept, unfortunately. It's not an exact > number I believe is cared about, but that one can "observe" (by what ever > methodology) an image has more tones than another image, rather than knowing > the exact number. I'll have to really think about that, as the "number" of > tones will be a range I believe, and not fixed... I very much understand visually what you are getting at, or at least I think I do. The best example I can think of is say comparing an 11x14 print made by enlargement from a 35mm neg to an 11x14 print contact printed from an 11x14 neg. For me personally the larger negative has a tremendous appeal as a printer. I am one of those rare photographers who actually enjoys the printing part of the process the most. I still am a "binge shooter" who goes out with the idea of gathering more negatives to print rather than a seeker after images. (I am not sure I am making sense or not, and I certainly can't recommend this as a way to practice the art of photography.) So if you could shoot exactly the same scene starting with 35mm 400 ASA film, then move to 50 ASA film, then to 6x6 100 ASA, 6x7 100 ASA, 4x5 100 ASA, 5x7, 8x10 11x14, 16x20 and 20x24, and then print them all to 11x14 we could sit down and look at the results and say this is what I mean by improved or greater tonality. I suspect that we would be in general agreement. I also think that we would see that the changes from step to step diminish with less and less perceptible improvement in tonality as we go up in negative size. At an 11x14 print size I cannot always see any meaningful difference between prints from my 6x7 and 4x5 negs. I believe there are several factors involved. There is the size of the image grain in the print, the amount of contrast between individual grains and the resolution (as in line pairs per mm) of the print. Coupled with this are the viewing conditions including level of illumination, viewing distance and the quality of the eyes involved. I doubt that print emulsion or dither pattern is a large factor except in relation to close viewing distances. I think a lot of it has to do with resolved fine texture and how that relates as variation in tone. I know that all of this is very real but I do not know how to quantify it in a single value or even a small set of values. My feeling is that even if I could, the decisions would be largely artistic choices. Martin (snip)