I'm am trying to apply some zone system technique to my 35mm b&w work. I have figured out my exposure indexes for Tmax100 and Tmax400 in D76, by exposing for Zone 1 at different ISO speeds and choosing the speed that gives me the correct density for zone 1, than assigning that speed. I'm aware that shadow density changes very little with different development times, do I just use the same EI for developers other then D76, and just concern myself with changing development times for highlights and contrast?

-- Frank Costa (red_rover@email.msn.com), August 05, 1999

Answers

I don't think that would work much better than any other flat-rate recommendation like "Usually it will be fine, if you halve the ISO speed and cut the development time by 10%." To fully comply with the zone system you must indeed determine the EI and development time for each film/developer/development method combination. If you want to get the very best out of your negatives, you would even have to calibrate your EI/development for the intended print size. (This is due - at least in part - to the Callier effect.)

I think your statement that shadow density vaires only little with different developers results from experiments with only a few developers which happened to give that result. If you try, e.g., the same film in Ilford's Perceptol and Microphen developers, you might find EI differences corresponding to an f stop or more.

If your intention is to bring "some zone system technique" into your work, I would recommend a different approach:

1) Do not use too many films and developers. If you have found a combination of film and developer that works for you, stick with it, or you might end up dragging around a dozen camera bodies with films particularly suitable for rare situations.

2) The zone system was not intended for films where many different images occur on the same roll. Thus, a strict application with 35 mm is hardly possible unless you carry around a camera body for each development category. OTOH, a lot of progress has been made in emulsion technology. Some combinations of modern films and developers have hardly any shoulder relevant for common images. That means that even zones IX and X, sometimes even XI have detail that can be made to print by appropriate darkroom technique. So the EI is still the most important parameter as it determines shadow density. (In spite of all the progress, you can't print anything from a clear film base.)

3) To bring *some* zone system into your work, I would recommend that you rely on spot metering to determine the appropriate exposure for the shadows and, if necessary, to check the highlights and mid-tones. If you use two camera bodies, one for "normal" stuff and one for very contrasty or very low contrast situations as the case may be, you will be fine. Note, however, that especially with 35 mm the expanded developments (N+1 and N+2 ...) are somewhat critical. I have read in Roelfsema's book (I'm afraid this is only available in Dutch and German.) on the zone system that hardly any 35 mm film gives satisfactory negatives with N+2. The compressed developents (N-1 ...) are a bit less critical.

4) If you wish to read a little about exposure and easily practicable film calibration (but only very little about the zone system) I would suggest two books by Roger Hicks and Frances Schultz, namely "Perfect Exposure" (this one covers b&w and colour) and "The B&W Handbook - The Ultimate Guide to Monochrome Technique"). Both are fairly recent books (1997 and 1999 resp.).

To conclude this: Some 15 years ago I had practically the same idea about my photography because I was frustrated with the results of quite a few shots under critical lighting conditions. (To put it in plain words, I more or less screwed up.) Reading about the zone system and using a spot meter (but without any explicit calibration of my development) were the cure for most of my problems. Later on (when I could afford a second camera body), I did stick to the zone system a bit more strictly, but with modern films, I take it far more easy again. I stick with spot metering most of the time, but only in extreme situations I adapt development and EI. If there is fairly high contrast, I give it a little more exposure and cut development a bit, or if contrast is very low, I cut exposure and expand the development a bit. The rest is done at the printing stage.

-- Thomas Wollstein (thomas_wollstein@web.de), August 06, 1999.

In my experience, yes, for the best results. If I changed my developer (or film), I would run my standard tests. These tell me the EI and contrast at different development times. It is true that the EI may not change much, but the tests are really for contrast, and the EI result comes 'for free'.

In case you are wondering, my standard test is simply to guess an EI, and photograph a grey card in Zones 0, 1, ... XV (or thereabouts), including half-zones. The densitometer then tells me the correction for EI, and the contrast. One roll of film per development time. This also gives me information about any shoulder, toe shape, and grain.

The test would use less film if I photographed a step-wedge, but I find that rather awkward.

-- Alan Gibson (Alan.Gibson@technologist.com), August 06, 1999.