zone system : LUSENET : Large format photography : One Thread


Does anyone have a simplified way of understanding and using Ansel Adam's zone system. And do you know about the Normal minus/normal plus processing techniques. The exact time differences in Normal minus and plus when you process in D76 at 20 degrees centigrade.


-- dileep prakash (, July 31, 1999


Wow, is this gonna be a long thread! I'll give it a shot.

Ansel Adams' Zone System is a method of previsualizing the tonal range of a scene as translated to the final print. It takes the concept of exposing for the shadows and developing for the highlights to a higher level. By measuring the brightness range of the scene, deciding upon what shadow and highlight areas in which you wish to maintain textural detail and determining what, if any filtration will be required to alter certain tones, you can plan the needed development for the exposure with predictable results. Mark Lindsay put it more eloquently in another's applied sensitometry!

That being said, I'll now try to help you get started. When you have your scene composed, take a long hard look at it and select the darkest area in which you would like to see distinct textural detail appear in the final print. Aim your spot meter at that area (I'm assuming you're using a meter equipped with a zone system scale) and place that reading directly across from zone III. Next, find the lightest area of the scene in which you want to see distinct textural detail in the final print and meter it. Don't realign the meter, just observe what zone in which the second reading falls. If it falls in zone VII, use the approriate aperture and shutter speed indicated by the first reading and plan to develop that negative normally. If the second reading falls in zone VIII, N-1 development is indicated. If the second reading falls in zone VI, N+1 development is indicated. That's pretty much it, the first meter reading determines exposure and the second, development. By the way, I put my film holders in zip lock bags and stick labels on the bags that identify all this info. for ease of sorting it all out later. I transcribe this info to my negative storage pages so I can review, over time, what I did when.

Now, these are very general guidelines that must be tried and tweaked a bit to take into account your materials and tools. Same goes for the processing. I generally use a change in development time of about 15-20% per zone of shift.

Why all of this works is pretty simple. The thinnest portions of the negative, the areas that are in shadow, are pretty much fully developed by the time 1/2 of the prescribed development time has elapsed. The highlight areas, which are the dense portions of the negative, continue to develop and get increasingly denser with time. If you shorten the prescribed development time, you'll prevent those dense areas from getting so dense as to completely block out detail. If you prolong development, you'll add density to these areas and increase the range of contrast on the negative. Pretty neat, eh?

I just know many of those experienced in all of this are reading in frustration while gouging chuncks of foam out of their mousepads, at the thought of such a very simplified explanation. My apologies to the offended, but I feel the most important thing you need to do when learning something like the zone system is to first understand the fundimental premise of it and then practice some basic technique to prove to yourself that it all works. Even if your early results aren't perfect, you'll be getting your feet wet and once familliar with the process, you can then read and understand the many books that have been written on the subject and fine tune the method to your working habits.

By the way, I do recommend Ansel's "Examples: The Making of Forty Photographs". Not only is it full of helpful insight to how he made many of his most famous images, but it's full of interesting background on his travels.

Best of luck in your new endeavor. Bob Zeichner

-- Robert A. Zeichner (, July 31, 1999.


The quick and dirty answer re deveelopment times is 1/ use the manufacturer recommended times for normal 2/ use about 33% extra time for N+1 and 3/ about 33% less time for N-1.

As you've probably guessed from the imprecise words, this might all warrant some testing on your part. Some people seem to... well, not enjoy testing. In that case, these times form good starting points. Check your negs over a period of time and adjust the times to suit your system and working methods.

If you do decide to test the material you use, test the entire system. Start with testing the papers you use with your enlager. Print step tablets to find the range of each paper. This tells you what density range on the negative each paper grade/filter can handle. Then test your films and development times to see the subject luminance range which gives you the density range you want on the negative.

In my opinion, most of this is mechanics once you understand the basics of sensitometry/zone system/whatever which is that exposure pretty much determines shadow densities while exposure and development determine highlight densities. All that the mechanics achieve is to allow you to calibrate you equipment and working methods to your deesireed finished result (which can be an important thing to do - something I came to appreciate only after trying to print my negatives on multigrade paper with an ancient cold light head, why the devil was I having to use filter 0 all the time, my negs looked OK - surprise, surprise, the cold light is heavy in blue light which gives harder contrast with the multigrade papers)... The most critical thing to develop is the ability to previsualize a scene i.e., in you minds eye, see a finished print you would like. Something I'vee found helpful is to actually try using some pencil and paper to sketch the scene and roughly sketch the tonal values - each picture takes quite a while to make but its quite contemplative and deliberate.

Some books I've found useful are 1/ Ansel Adam's books (esp. 'the negative' and 'the print' - quite accessible and inspiring) 2/ phil davies 'beyond the zone system (in his own words - it's like taking a cold shower: you'll find it difficult to get into and may not even enjoy it while you'ree in it but you'll feel great afterwards) 3/ the standard tomee is one by minor white et al.

Hope this helps. DJ

-- N Dhananjay (, August 01, 1999.

The best explanation of the Zone System is in Bruce Barnbaum's "The Art of Photography". It is also one of the best books ever written on photography in general.

-- Mark Lipton (, August 02, 1999.

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