My first stumbling steps into the zone system...

[vicmortelmans]

I'm trying to get a grip on some concepts of photography and the zone system. Waiting for getting hold of the book, I'm collecting information from the web and I must say, either I am stupid, or few people really understand about it, but don't hesitaty to write about it.

Just a first step: I understand that the zones defined by Ansel Adams are numbered gray tones from 0 to X. They apply to gray tones as they would be percieved on a print (1). Each next zone is twice as bright as the previous. The middle zone (V) is defined to be as bright as a standardized 'gray card'.

Now, please help me out! A gray card is defined to reflect 18% of the incident light. The reflected light actually defines the brightness of the object. If zone V reflects 18% of the light, and zone VI is twice as bright, it reflects 36% of the light. AM I WRONG? Zone VII 72% and zone VIII 144%... I don't think something can reflect 144% of incident light, can it?

Help me out, how did Adams really define his zones? What did I misunderstand about the words 'brightness', 'reflection', 'tone','gray card',...???

Groeten,

Vic

(1) first very important understanding: a zone is *not* specifying an absolute value of light intensity! Because if you look at a print in sunlight or under a 60W lightbulb, you'll perceive the same gray tones, but the actual light intensity will be quite different!

 

[Wayne R. Scott]

I think you are confusing exposure values with percentages. I can make a gray card look black, gray or white in the same amount of reflected light by simply changing my exposure times and/or lens aperature.

Say an exposure of f8 @1/125 second will render my gray card "correct", then an exposure of f16 @ 1/500 second will render it black and an exposure of f4 @ 1/30 will render it white. The card and amount of reflected light have not changed, just how long I "cooked" my film with reflected light. Kinda like making toast, raw, right, cremated.

Wayne

 

[vicmortelmans]

You describe how you can 'place' the gray card in another zone. Expose at f8 @1/60 (one stop exposure above the "correct"), the zone system says you have 'placed' the gray card in zone VI (while on a well calibrated system and "correct" exposure, it should be in zone V). But how do you define then this zone VI, if not compared to zone V by the actual brightness of the print it produces.

Zones need a definition independent of film, camera, exposure or development parameters.

As I understand the Zone System, you basically have the brightness of the objects in the scene you're photographing (expressed in light values or candela per square meter) on the one hand and the grayscale tone of the image on the final print on the other hand. The latter is expressed in 'zones'. Inbetween scene brightness and zones lies (1) film choice, (2) camera meter, (3) exposure setting, (4) development and (5) print. These five parameters define how brightness is mapped to tone. And if you have a calibrated system (film, meter), you can use exposure and development (and print) to actually 'place' brightness in a particular zone.

I love the concept, but don't understand the definitions, so probably I'm completely lost somewhere.

Groeten,

Vic

 

[kaiyen]

Well, first of all, I highly doubt that, as you move from zone to zone, the reflectance change linearly. It's quite possible that zone VI is, say, 24% reflectance rather than 36, for instance.

My knowledge of the zone system doesn't extend into the depth you are seeking. I presume you are getting The Negative? You should also probably consider Beyond the Zone System, too.

good luck,

allan

 

[Wayne R. Scott]

Wow! This is tough. I think that you will find that a paper print does not have 100% reflectance to begin with maybe 90 to 95% depending on type of paper. Printing paper can only reproduce a luminace range of about 40:1. The human eye can resolve a range of luminace of something like 1,000,000:1 (dim starlight to bright sunlight and higher). But not at the same time. It is almost impossible to record a scene on film and then reproduce it exactly on paper. Artist license should be used when printing.

The relation ship from one zone to the next is not linear I believe it is geometric.

Luminace and reflection are not the same thing.

Camera meters are not calibrated to read 18% gray. I think they are set to an ANSI standard of somewhere between 12% and 14%. About 1/2 stop less than 18% gray.

Sheesh, I forgot what your question was. Hope this helps confuse you even more.

Wayne

 

[the_other_dirk]

Luminace and reflection are not the same thing.

I think so too.

This is how I understand it: hold a grey card at 1 meter from a light source. Take a reading. Now move the card back and hold it at 2 meters from the same light source. Take another reading. You'll notice that you have lost 2 stops. So, the luminance has reduced by two zones. But the reflectance of the grey card has remained 18%...

So if you had two grey cards, one positioned at 1 m from the light source, the other at 2m and took a photograph, I guess you'll see that the second grey card has a lower luminance (corresponding to two zones less exposure I think) than the first

 

[RayPA]

...Now, please help me out! A gray card is defined to reflect 18% of the incident light. The reflected light actually defines the brightness of the object. If zone V reflects 18% of the light, and zone VI is twice as bright, it reflects 36% of the light. AM I WRONG? Zone VII 72% and zone VIII 144%... I don't think something can reflect 144% of incident light, can it?

Help me out, how did Adams really define his zones? What did I misunderstand about the words 'brightness', 'reflection', 'tone','gray card',...???

Groeten,

Vic

Hi Vic,

I am by no means a zone system practioner, or student, but I always understood each zone to be based on exposure, with the ratio being 1:2. If you are speaking of zone V, it would represent twice as much *exposure* as zone IV. You should probably keep the whole percentage-thing, and gray cards, out of the equation, while trying to absorb this stuff. BTW, I believe practioners consider a normal zone scale to be anywhere from 9 to 11 zones. 🙂 This thread is starting to fire some memory synapses, I vaguely remember headaches from trying to previsualization and I remember metering ad nausem, compression and expansion...N+1, N-1...aaargh! 😉

🙂

 

[Gabriel M.A.]

Camera meters are not calibrated to read 18% gray. I think they are set to an ANSI standard of somewhere between 12% and 14%. About 1/2 stop less than 18% gray.

Is that true?? That explains a number of slightly misexposed pictures. So ANSI is like Microsoft, eh, the world has a standard, but they have to set another??

Middle gray has always been understood as 18%, or "Zone V" in the most basic, 101 chart. All gray cards are 18% ref. (unless they are ANSI??) I wonder if that's why digital cameras cameras have adopted White Balance vs. Middle Grey Balance.

 

[vicmortelmans]

Hi Vic,
I am by no means a zone system practioner, or student, but I always understood each zone to be based on exposure, with the ratio being 1:2. If you are speaking of zone V, it would represent twice as much *exposure* as zone IV.

That's also what puzzles me: according to the zone system, you cannot only 'place' an object with certain brightness in some zone by changing exposure, but also by changing development. Exposure control is like shifting the zone card along the brightness scale and development control is like taking the zone card on the left (the shadows) and stretch or compress it from the right (the highlights).

In this view, you cannot define zones just by exposure.

I get the impression that the zone system is not so much a scientific approach to control photography, as well a set of mental concepts that help the photographer to visualize the effect of his operations.

Groeten,

Vic

 

[kaiyen]

I get the impression that the zone system is not so much a scientific approach to control photography, as well a set of mental concepts that help the photographer to visualize the effect of his operations.

I think that is _exactly_ what the ZS is. It's a way of taking a scene, visualizing how you want it to come out, then giving you a set of tools/procedures/concepts that will allow you to achieve that result.

allan

 

[Wayne R. Scott]

Bingo. I think this is what Saint Ansel was getting at when he said to pre-visualize a scene.

Wayne

 

[torhan]

I read about the zone system 10-15 years ago and I never adopted it to my practice. My conclution was that it's for photographers with a spot meter and a large format camera. Spot meter to take readings of objects in the picture and place them in a certain zone and a large format camera to take just one picture at the time and develop it to the right contrast.

I also read that camera light meters are calibrated to zone 3½ and that's very close to the tone in a white mans palm in shadow. In this case, lucky me that I'm white. I just put my back to the light source/sun and open my hand in my own shadow, point my camera to it and get an exposure reading. Now I will have details in the shadows in my pictures.

To have a slight control of negative contrast, reduce developing time if it's a very sunny day or great contrast in the picture and increase time if it's overcast or a dull day without shadows. My rolls are almost always taken in so different situations so I just use standard developing times nowadays

This is not the zone system but maybe zone system 'light' that's easy to learn and fast to practice for a street photographer. Not much of an answer though. My suggestion is to get the book and read and understand it to get better control of your pictures but don't be a slave to it.

 

[xcapekey]

uh.....beware the zone system....many get lost in its labyrinth of technical overcomplexity and start shooting beautifully toned images of really boring things 🙂

in all seriousness, i think the ultimate point of the zone system is to think and pre-visualize instead of random shooting and it seems to be based on the assumption that in-camera meters are stupid (which they can be) and that we're stupid (which we are) if we go along blindly with what the camera/meter says without consulting our sensibilities...

it's like compensating for brightness on the beach....you know that the camera is going to underexpose if you point it at some bright sand, so you open up two stops...in Zonespeak it sounds like "well, if i meter the sand it places it in zone V when it should be really in VII so i'm going to adjust exposure to place the sand to VII by adding two stops overexposure..."

or let's say you're shooting a dark cave or cavern which zonies are also fond of photographing...you know that you want shadow detail so you open up a stop or two to capture it and if there's a highlight in the scene that you don't want to lose you either decide to burn it down in printing or cut the development to save it...but in zone speak it sounds like rocket science....

another quote from AA...nothing is worse than a sharp picture of a fuzzy idea.... it's corrollary applied to the ZS ...nothing is worse than a beautifully mutlitoned photograph of a flat singledimensioned idea...

 

[zpuskas]

Boil it down to basics...expose for the shadows and develop for the highlights. Previsualize where you want your darkest (still with detail) shadows--take a reading and place in Zone III. Take a reading of your highlights where you still want detail and place in Zone VII. If the difference--in your meter reading between where you want Zones III & VII--is more than 4 stops, decrease development (you'l have to experiment here). If it's less than 4 stops, increase development.
I suggest reading Carson Graves' book "The Zone System for 35mm Photographers". He taught me how to use the Zone System in college.

 

[Roger Hicks]

The Zone System is an oversimplification of basic sensitometry in one sense, and an overcomplication in others. Basically, until you have enough sensitometric knowledge to understand it, it is of very limited use, and once you do know enough about basic sensitometry, you don't need it.

There are five free modules in the Photo School on www.rogerandfrances.com that should answer many of your questions, including one on density, the D/log E curve and gamma; one on 18 per cent grey cards; one on ISO speeds;and one on why I don't use the Zone System. My book Perfect Exposure (David & Charles, 1999; reprinted 2000, 2004, ISBN 0-7153-1992-2) also has a lot of the underlying theory of basic sensitometry

Even so, here are three points to begin with:

Perception of tones is not linear but more or less logarithmic. If you lay out a set of cards from maximum black to maximum white most people will pick around 18 per cent as a mid tone.

This has NOTHING to do with average reflectance, which is indeed around 12 to 14%: broad-area meters are indeed calibrated to this, because calibrating them to 18 per cent would be useless.

Far from being about 40:1, as the old books recite, the maximum brightness range of a glossy print, optimally lit, is around 200:1 (log range 2.3 to 2.4, or more with the right paper) and the dynamic range (the range across which you can see detail in both the shadows and the highlights) can approach 100:1 (log range 1.95 or better). You can easily confirm this yourself with a densitometer.

I would most heartily recommend that you do not waste your time with the Zone System. When I was in your situation, some 25 or 30 years ago, I wasted an immense amount of time trying to master it -- time that would have been far better spent in taking real pictures, not faffing around with grey cards and N/N+/N- development.

When I came back to it, a decade or two later, I could see exactly why I had found it so difficult. It is laden with jargon, and because it was formulated in an era when densitometers were rare, expensive and unreliable, it had to rely on visual comparisons which are needlessly time-consuming today.

Finally, consider this. Ansel Adams was a very good photographer. This had little or nothing to do with the Zone System, which was formulated well after he had already reached the peak of his powers. To conflate his skill as a photographer with his exposition of the Zone System is a logical error of the first magnitude.

Cheers,

Roger

 

[mattg]

Hi Vic,

I have found the Zone System a useful tool for understanding how to make choices when taking photographs and developing film. I have never applied it fully as I don't own any sheet film cameras.

About all I do is make sure that important shadow detail is underexposed by no more than about 2 stops and then if I know I've been photographing really contrasty scenes I'll knock about 15% off my developing times (found by trial and error with each film, not densitometry) to keep the highlights as controlled as possible. I really don't think you need to do much more than this.

By all means read the books, I think the series is just as useful for all the incidental information contained and the wonderful images.

 

[Roger Hicks]

I'm right with Matt on this one. Meter the darkest shadows in which you want texture and detail and then give 2-3 stops LESS (depends on meter, technique, film, personal preference), then 15% less development for contrasty scenes, that'll do it.

Cheers,

Roger