Contrast control questionsgreenspun.com : LUSENET : B&W Photo - Film & Processing : One Thread
From my understanding of the "zone system", contrast can be controlled by under/overexposure, and extending/reducing development time (correct me if I'm wrong).
Are these techniques only used for large format photography, since an entire 35mm roll would have to be developed the same way? How do the results of these techniques differ from printing on different contrast grades of paper?
Thanks for your help.
-- Walter Newton (email@example.com), September 24, 1997
The overall contrast is mainly controlled by the film developing time.
Under/Overexposures have a marginal effect on overall contrast changes, unless your image heavily involves the toe (or the shoulder) of the film curve (in which case the image is probably lost....). However, slight exposure adjusments are often necessary to compensate the effects of reduced or extended development.
Basing upon my B/W printing experience, the use of different paper grades to accomodate for film's contrast changes allows only small adjustment of the image contrast.
Specifically, trying to print a contrasty negative upon a "soft" paper is frustrating: the tonal range is often severely limited and - due to the low-contrast paper - the picture looses "strength" in shadows and higlights. Hours of work under the enlarger, with HEAVY use of dodging and burning techniques often draw to poor results.
The situation is dramatically different when you put a "good" negative under the enlarger: the first print over normal grade paper is usually satisfactory. With little intervention, the results can often be excellent (technically speaking, obviously). In this case, a slight change in the paper grade can be successfully used to "fine tune" the tonal scale of the image !
Incidentally, it's not a case that the "Zone System" was ideated by a Large Format photographer: the development can be adjusted for EACH shot, with maximum-level results.
However, you can apply a "reduced version" of the Zone System even using Medium and Small format cameras, provided that you own three (or, at the minimum, two) film-backs or camera bodies.
Load the three film-backs (or the three bodies) with the same film, and label them "N", "N+1" and "N-1", respectively. Then, shot your images using the appropriate film back (or body), basing upon your exposure meterings.
You will end up with three rolls in your hands, each containing images sharing almost the same overall contrast. Obviously, they will be processed accordingly to the label affixed.
Provided that you carefully determined your N, N+ and N- developing times, the results will be outstanding: the three combinations - in my opinion - cover 95 percent and more of the photographic situations you will encounter. Moreover, consider that an "N+2" subject can be shot on a "N+1" film with less image quality loss than that obtained by shooting it on an "N" roll !
A further reduction of the method is possible: prepare only "N" and "N-1" film backs: if you face an "N+" subject, soot it on the "N" film and work with paper grades to adjust the image. The results obtained by printing "soft" negatives over "hard" papers are quite better than that obtained by "hard" negetives over "soft" papers.
-- Carlo Rogialli (firstname.lastname@example.org), September 26, 1997.
Just to add to Carlo's comments, an alternative to having a number of cameras is to roll your own film and just load 10 frames (or less) into the canister. Loading your own film is a much cheaper way to operate anyways (<$2 per 36 - for 35mm). This way you can easily devote a whole roll to the same subject and develop accordingly.
-- Andy Laycock (email@example.com), September 29, 1997.