Actual zone system

[Bernard_L]

Then, determine the normal (N) development time to be that development time that renders a Zone VII area in the scene (on the negative) to be 2.35 density units . (This 2.35 is very close to the Zone VII value that John Sexton uses.) Of course, this requires a densitometer. But personally, I would never engage in zone system preparation without a densitometer. (I have a Tobias densitometer that works very well for me.)

2.35 ??

Do you mean 1.35? Even that sounds more like a target for zone VIII, but I would not argue very ong about that.

[Tin Can]

I always guess FIRST

then meter

try tt

[Tim Meisburger]

The zone system is usually explained in a weirdly complicated way. Let me see if I can make it clearer (probably not). The human eye can see tones from brilliant white to absolute black. At the beach we can see tones in the white sand under the hot sun, and the texture of a towel in the deep shade under a beach umbrella. Paper (and film) doesn't see that well; it can only record tones from almost white to almost black, so in a print the beach becomes textureless white and the towel featureless black. The paper can only see the middle tones.

Imagine we have divided the spectrum from pure white to pure black into eleven tones (called zones), but our film or paper can only see five. In a contrasty scene, you want to darken the highlights slightly to push them down into the readable range of the film so we can get some detail, a process called contraction. In a flat scene you might only have a three zone range, so to get more contrast we want to make the darks a little darker the the highlights a little brighter to use to the full five zones we have available, a process called expansion.

The zone system asks you to evaluate a scene to determine the contrast range. If it is greater than the recording ability of the film or paper, we contract. If it is less, we expand.

Most people these days do contrast control with filters, rather than modifying development, but no matter what you need to ensure you have sufficient exposure so there is detail in the shadows to modify. The film can only see detail down to zone three, and below that the film in that area will be clear, and in the print pure black. But your eye can see detail in shadows down to about zone one, so to get detail in the shadows, we have to overexpose that area (relative to your eye), and push zone one shadows up to three to get detail in our print.

People often talk about "placing" an area in a zone, and this can be confusing, if you don't know how a lightmeter works. A normal lightmeter looks in a general direction and averages all of the light it sees. Dark areas reflect less light to the meter and bright areas reflect more light. The meter averages those values and tells you to set the camera to record the average value as the middle grey tone between black and white (zone 5). Usually, that works okay, but what if the subject is a painting of a snowman on a white wall, or a black cat on a black wall?

The meter reads and averages the light reflecting from each wall, and gives you an exposure that will yield middle grey. So in the exact same lighting conditions, the meter will tell you to set the camera for the snowman at f32 and 1/100 second, but when you meter the black wall it will tell you to set the camera at f8 and 1/100 for the cat. In both cases, when you print your negatives, the snowman will be zone five middle grey (not white) and the cat will be zone five middle grey (not black).

The snowman is too dark (under-exposed), and we want it to be white in the print, so we can make it brighter by adding two stops of exposure (placing it in zone seven) by opening up to f16. The cat is too light (over-exposed), so we can make it darker by subtracting two stops of exposure, and stopping down to f16 (placing the cat in zone three). In the end, the correct exposure for both scenes is f16 and 1/100th of a second.

So, say you have a forest scene that includes interesting leaves in the shadow of an overhanging rock, and you want to be able to see those leaves in the final print. With your spotmeter (or averaging meter held close), you measure the exposure in the shadow. If you set your camera to that value, the leaves will be middle grey (zone five) in the print. Since you want your shadows to be shadows, but still light enough to show detail, you stop down two stops, "placing" your shadows in zone three. Similarly, if you want your snowman to be white, meter it, then open up two stops, "placing" it in zone seven.

Hope this helps.

[Tim Meisburger]

Back in 2011, SM Booth shared Gem Singer's simple explanation of the use of expansion and contraction in practice, which was the best I've ever read. Impressed me so much I printed it out and carried it around for years. The link to the original is here, at post #5 (and Gem's response at #6): https://www.largeformatphotography.i...for-Landscapes

Here is the relevant text:
Aim the one degree spot at the darkest area in the scene where you still want to see some detail. Close down two stops. You have just placed the shadow area in Zone III. That's usually the proper exposure for the scene.

Now, aim the spot at the brightest area in the scene. If it's a five stop range between the darkest and brightest reading, use normal development. Less than five, increase development. More than five, decrease development.

No need to take a whole series of meter readings and average them. That's defeating the purpose. Just make certain that you have given enough exposure to get some detail in the shadows. Then, develop for the highlights. That's the Zone System in a nut shell.

[BrianShaw]

The primary reason I use a spotmeter to take multiple measurements and average (or use a spot meter at all) is to remind myself that, more often than not, a single general-coverage or incident reading is just as effective. I find a spot meter to be better used as a training tool for learning to see light levels to discern when a spot meter really is a better metering tool.

[neil poulsen]

2.35 ??

Do you mean 1.35? Even that sounds more like a target for zone VIII, but I would not argue very ong about that.

I just noticed that. Indeed, it's 1.35. Thanks!

And yes, it's probably somewhere between Zone VII and Zone VIII. I originally chose this value as a bit high for the paper that I use, which is Ilford warm-tone fiber. (I would likely choose a somewhat higher value for resin paper.) It works well for me in how I visualize.

Then, in a John Sexton workshop I attended, I noticed this value's close proximity to his Zone VII.

[neil poulsen]

. . . Most people these days do contrast control with filters, rather than modifying development, but no matter what you need to ensure you have sufficient exposure so there is detail in the shadows to modify. The film can only see detail down to zone three, and below that the film in that area will be clear, and in the print pure black. But your eye can see detail in shadows down to about zone one, so to get detail in the shadows, we have to overexpose that area (relative to your eye), and push zone one shadows up to three to get detail in our print. . .

This is true.

But to really get the best black and white results, it's important that the NEGATIVE have the correct contrast. This is what the Zone System is able to accomplish. If the negative contrast is off, no amount post-fiddling with filters (for variable contrast papers) will correct for this initial inadequacy.

[Corran]

If the negative contrast is off, no amount post-fiddling with filters (for variable contrast papers) will correct for this initial inadequacy.

Isn't that the exact purpose of filters on VC paper?? I've definitely made less-than-perfect negatives, especially on roll film, and boosted contrast with #4-5 filters.

[Tim Meisburger]

This is true.

But to really get the best black and white results, it's important that the NEGATIVE have the correct contrast. This is what the Zone System is able to accomplish. If the negative contrast is off, no amount post-fiddling with filters (for variable contrast papers) will correct for this initial inadequacy.

Yes, I agree. Truthfully, I've never been satisfied with a print I've made from a bad negative.

[Tim Meisburger]

Isn't that the exact purpose of filters on VC paper?? I've definitely made less-than-perfect negatives, especially on roll film, and boosted contrast with #4-5 filters.

I think this depends on what we call a "good" negative. For me, if I can achieve what I wanted with the negative through the use of contrast filters, it is a good negative. Because of the latitude of film, there can be several exposures that will yield a "good" negative.