When making black and white prints, there is a limit to what can be done to save a bad negative. It is often a struggle, and one that can be avoided by not making bad negatives in the first place. And among the many solutions to this problem, the one that gets the most press is the Zone System.

Background
Neither exposure nor development will build density alone. It is only in the right combination, that the optimum negative is produced. For this, the science of sensitometry was developed. It took hold in the early days of the movie industry, when scenes shot in different places were spliced together so that they appeared continuous. They had to match. The light was carefully controlled and H&D curves were used to monitor the processing. It worked. It was, and still is, the most accurate way to control contrast and density. But this is due in large part to the tight control over lighting ratios that were used on the "set."

If the sun was too hot, auxiliary lighting "filled" the shadows. If it was overcast, the same lights were used to produce shadows. And all the film was processed to the same optimum gamma, or contrast. And Ingrid Bergman didn’t look 20 in one scene and 50 in the next.

But still photographers, who may not have had trucks full of lighting gear, needed another way to control the image. For this, the Zone System was developed. By using a spot meter and calibration testing, it made the process fit the scene rather than creating a scene or "set" to fit the process. One could visualize a final image and, by manipulating exposure and development, realize that image.

Developed as a teaching aid by Ansel Adams and Fred Archer, the Zone System gradually turned into a religion. Spurred by those who need a handle on a devilishly unwieldy medium, it offered a simple credo: Expose for the shadows and develop for the highlights. And although most professionals shortcut and even avoid the Zone System altogether, it has enabled generations of photographers to realize their vision with a minimum of frustration.

No discussion of film response would be complete without mention of local contrast and memory values. Skin tones are memory values. We know from memory what human skin should look like – not just in a light or dark way but in terms of contrast….local contrast. With too much or too little contrast, a flesh tone doesn’t look right, which is why the movie industry and most portrait photographers do not use the Zone System - since the Zone System is about manipulating contrast. On the other hand, rocks, lakes and sky are not memory values. There are rough rocks, smooth rocks, light rocks and dark rocks and no one really cares one way or the other – a subject matter made to order for the Zone System.

The Zone System came about when equipment and materials had not reached the standards of performance that we have today. Film and paper manufacturers had different interpretations of normal contrast. Shutter mechanisms were crude and seldom accurate and lenses, being uncoated, would react to flare in a wide variety of ways. The Zone System offered a way to compensate for these variables by creating a custom process.

Today, that is less of an issue. Copal Shutters are as accurate as they are consistent. Lenses are double coated and meters are precise and stable. Film and paper, as well, are tested by manufacturers who maintain quality controls that were not evident in the 40s. Photographers never had it so good. As long as our gear is adjusted properly*, we can calibrate our process to a normal target and feel confident of success.

That is the underlying premise of my abbreviated Zone System. Although derived from a loose mix of experience and technology, it is as accurate and serviceable as any other system that I have tried, and by far the easiest.

Before you start
You will need a reflective test target consisting of 6 squares, each 1 stop apart and labeled as such: +3 (the darkest), +2, +1, N, -1 and –2 (the lightest). The squares need to be large enough to read with your meter and have uniform surface texture. Making one is not easy, but once you have it, you will never have to do it again. Mine was made many years ago, by spending the better part of an afternoon in the darkroom tweaking the squares to within .10 EV, using a spot meter. Today, it would be much faster using Photoshop. In use, the target needs to be illuminated evenly to avoid glare.

Some points to ponder
A lot of discussion surrounds the establishing of film speed, with different people having film speeds that vary by as much as 3 stops. There is no reason for this. The same film in the same developer should have the same film speed, no matter who is using it – if, as said before, everything is adjusted properly*. So here is where a little theory and experience can save a lot of time: by separating film into two categories – thin emulsion and thick emulsion – you can arrive at a speed that will work 99% of the time. It goes like this: with thin emulsion film, use the manufacturer’s recommended figure; with thick emulsion film, reduce the speed by 30%. Keep in mind that manufacturers want to rate their products as high as possible. Furthermore, they do a lot of testing, and their data tend to be quite accurate.

So, why fudge one rating and not the other? It has to do with the limitations of thin emulsions (low speed, fine grained). Since the entire emulsion thickness is exposed – and blocked up – more readily with thin emulsions, over-exposure comes with a price. The highlight values go quickly onto the shoulder of the curve and will appear dull and lifeless in your print. So, to get a richly toned print using a thin emulsion film, over exposure must be avoided.

Thick emulsions, on the other hand, have greater dynamic range or latitude. They can retain detail in highlight areas, even if over exposed. So for this reason, I reduce the film speed by 30%. Keep in mind what we said before about exposure and development working together - that little extra kick will, therefore,  enable you to achieve higher + developments.

Back to work
Using the duly determined ISO value, place the N square on Zone 8 and shoot 4 sheets of film of the entire target. Don’t forget to include bellows factor.

Referring to your film and developer data sheets, determine a temperature that should produce a normal neg at 6 or 7 minutes and process your negs for 3, 5, 9, and 25min. at that temperature.

Using a densitometer, read all the densities. On a piece of graph paper, put density on the vertical axis, and time on the horizontal axis. Plot a curve for each level of development so that N, +1, +2 etc. will have its own curve on the same set of axes.  You can use your own graph paper or that which is provided here: Density vs Time.   Then draw a horizontal line at about the 1.5 density level. Where it crosses the curves are your magic numbers. You can tweak the system by raising or lowering the line. But don’t fall into the trap of doing this on the basis of one or two shooting sessions. Look for a trend over an extended period before you make changes. I use a diffusion enlarger and have never had to use anything other than 1.5. If you are contact printing or using a condenser enlarger, start out with 1.3.

You will soon find that, for most situations, +3 is wishful thinking. If you are serious about it, however, simply use a lower film speed and maintain a separate set of numbers for high contrast renderings. Remember: all the development in the world is useless without exposure. Whether you get a true +3 contrast is still another question, since chemical fog keeps most materials from reaching that level.

With a nice hot hair dryer you can calibrate a film and developer combination in about 45 min.

In the field
To use the Zone System, find an area of a scene that you want to be black with detail, place it on Zone 2 or 3 and expose accordingly. To determine development, find an area of the scene that you want to be white with detail, and without moving the dial, see where that reading falls. If it's 1 stop below Zone 8 then process to +1; if it falls on Zone 8 then use Normal dev.. , one above Zone 8 is -1, etc.

Not all scenes present large enough "standard" shadow or highlight areas to read with your meter. For these situations it helps to have a bunch of paper scraps of varying densities at your disposal. Select one that matches a Zone 8, and read it normally.

After doing this for a while, you will find yourself determining degree of development by intuition and simply reading a zone 8 value and placing it accordingly.

* The foundation of any system is an accurate light meter. A modern digital spot meter that has been calibrated over its entire range is worth its weight in gold. Accurate shutter speeds are also necessary, especially in speeds faster than 1/60 sec. Slower speeds are fairly easy to verify by ear, and F stops are hardly ever an issue, except when lens elements are replaced with those of different focal lengths.

But equipment can fail, and when it does, it helps to have a backup plan. Mine is intuition - never take a meter reading without trying to guess it first. With practice, the accuracy that you can achieve is amazing.

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