Myth #3: Shadows should be placed at Zone 3 in the zone system
This is an idea about using the zone system that comes from the creator of the zone system himself. Ansel Adams urged photographers to place shadows in Zone 3, but I doubt that he used Zone 3 placement himself. His prints exhibit too much brilliance and illusion of spatial depth to have been given such low placement of shadows in his own negatives.
Let’s look closely at the exposure/density curve (Figure 9-5) to see why Zone 3 placement is too low and why Zone 4 placement turns out to be much better. The toe of the curve is the initial, lower portion of the curve that is rather flat. This part of the curve yields very low density separations on the negative and consequently very low tonal variations on the print. So you don’t want anything important on that part of the curve. (Note the emphasis on “important”.)
The major part of the curve, the so-called “straight line” portion, is not flat. It rises at a steeper angle, indicating that for equal increases in exposure of the negative you get greater density separations in the developed negative than you get in the toe of the curve. Let’s keep that in mind and consider what it means for a print.
Texture in any photograph is made up of small tonal variations in immediately adjacent tones. When you talk about Zone 3 texture or Zone 4 texture, you’re not just talking about a Zone 3 tonality or a Zone 4 tonality; you’re talking about small variations in tonality around that zone that comprise texture.
If you expose a shadow area at Zone 3, some of the densities on your negative are lower than Zone 3 and some are higher, yielding texture. They average to Zone 3. But if some of that texture is at Zone 2½ or less, it’s on the toe of the curve where density separations are lower. Therefore tonal separations in the print are lowered, and the print begins to look flat. The word “flat” perfectly describes the unsatisfactory print you get. The print has the following two main flaws:
It is tonally flat, lacking in the good tonal separations that give it snap.
It is dimensionally or spatially flat because nearly identical tonalities yield prints that lack the appearance of spatial depth.
To avoid the unsatisfactory look and feel of flatness, expose the negative higher on the scale at Zone 4. With higher placement, those portions of the negative higher and lower than Zone 4 are still on the straight line portion of the curve, yielding far better tonal separations in the print.
You may object that the shadow is then too light in tone. Of course it is, but you solve that problem by printing it darker—down to your desired Zone 3—when you enlarge it. When you do that, you’ll get a print with far richer tonal separations, one that exhibits far greater spatial depth. In other words, you expose and develop the negative so that the shadow densities are in the Zone 4 range, but you print it down to the Zone 3 range under the enlarger. It’s that simple.
David Vestal, in an article in Photo Techniques (January/February 1999) said, “For detailed black stuff, I expose only one stop less than indicated.” Thus, he found that he got better results when he placed shadow details in Zone 4 rather than Zone 3. Vestal also mentioned that Ansel Adams recommended Zone 3, but he himself found that “the resulting negatives are too thin”. Vestal is worth reading; he has a lot of worthwhile things to say.
You may inquire, why are we always taught to place the shadows in Zone 3? Because most teachers and most magazine writers are sensitometrists, not photographers. They spend too much time testing materials and graphing them and too little time making photographs. When they look at Zone 3, they look at an exact Zone 3 tonality, not at a textured range that averages out to Zone 3. There is an immense difference between studying an exact Zone 3 tonality (lacking texture), and a Zone 3 made up of texture. The photographer’s world is made of textures; the sensitometrist’s world is made of tonalities. The difference is like day and night.
Sensitometrists pull out their trusty densitometers and get the perfect Zone 3 by exposing a gray card at that zone. All appears to be well and good. But when they expose a real scene with real tonal variations and real texture, their exposed Zone 3 yields closer tonal separations because the textures are made up of tones both above and below Zone 3. Some of the tones below Zone 3 dip into the toe of the curve. With a Zone 4 exposure, nothing dips into the toe of the curve, so the separations are greater. When you take a negative with Zone 4 texture and print it darker (back down to Zone 3 tonalities), you retain greater tonal separations in your print. Look again at Figure 7-2 and specifically at the hill and rock area in the center, directly below the snow-covered mountain. That area was placed just above Zone 4 during negative exposure to retain maximum separations in those shadow areas, but printed significantly darker than Zone 4 to give the photograph the snap I sought. Had I placed those areas at Zone 3, I could not have maintained either the richness of tone or the feeling of depth that the image conveys.
Sensitometrists who work with step wedges and exact tones are like people who study a single musical note. Melodies, however, are made up of many notes creating a musical texture. You can’t get the feel of a melody by examining a single note. Similarly, you can’t get the feel of texture in a photograph by examining a single visual tonality. Sensitometrists are like piano tuners who make sure that each individual key sounds exactly right. You need them to keep the piano tuned, but you need a composer to write music and a pianist to play it. Photographers are both composers and pianists. It’s wise not to learn how to play the piano from a piano tuner. It’s equally wise not to learn about zone placements from a sensitometrist. I see too many sensitometric curves in photography magazines.
Photographs are not step wedges; they can be real art. They are meant to be personally expressive. They are meant to be seen by others and to move others emotionally. They are meant to communicate a thought, a mood, an experience, a moment in time, a fantasy, or any of dozens of other ideas from the artist to the viewer. They should be imbued with light and life. Exact curves and exact enlarging times won’t get you there. You’ve got to deviate from the densitometer readings and use different approaches from one print to the next if you want to say something.
I don’t own a densitometer—never have, never will. It gives me no useful information. All I need to do is expose and develop a few negatives to tell me everything I need to know about how a film responds to light and how a developer works with that film. I know that however little or much I develop a negative—minus development, normal development, or plus development—the lowest zones look just about the same because they develop quickly and hardly get any denser after the first couple of minutes of development. The low zones tell me the speed of the film and also whether I exposed it properly. Then I look at the high zones to see how much density they have, which tells me whether I developed the negative properly. If I’m off by a little, I adjust my development procedure. Any such readjustment won’t materially affect the low zones because they develop so quickly and so fully. Looking and adjusting is far better than testing.
In order to assure that I’m solidly above Zone 3 when exposing my negatives (i.e., above the toe of the curve), I generally set my film ASA considerably lower than the recommended value. For example, I shoot Kodak Tri-X rated at ASA 320, but for my purposes I rate it at 160 (a full stop lower than Kodak’s recommendation). When I shoot Ilford HP5+ rated at ASA 400, I shoot it at ASA 300, a half stop lower than Ilford recommends. I do roughly the same for other films I use as well.