The Zone System
The following information is taken from 'The Zone system
- A Basic Explanation' by Arsene Baquet and Steve Holtz. After
reading this information I felt that it gave an easy to follow
understanding of the Zone System so I decided to pass this information
on via one of my web pages.
Do you want to talk to others about the zone system? Click Here.
This text will present the Zone System in its simplest form.
The reader should already have a good understanding of the relationship
between aperture settings (f-stops) and shutter speed settings,
and be able to operate the camera manually in conjunction with
a hand-held light meter. This is essential for using the Zone
System.
Armed with this primer, the student will be in a better position
to tackle more detailed works providing an expanded view. I would
suggest "The Zone VI Workshop" by Fred Picker and "The
Negative" by Ansel Adams. But, keep in mind that the Zone
System is not a magic wand, or a guarantee of perfect prints.
It is simply one of many tools you will employ to achieve your
goals.
While this paper is copyrighted, it may be copied and distributed
freely. We ask only that it not be altered without permission,
sold, or used for commercial purposes.
The Zone System is a method of understanding and controlling
the exposure and development of the negative, and how to vary
that exposure to get the results you want.
Exposure, developing, and printing, are all interrelated.
The results of any one can (to an extent) be affected by the
others. This provides flexibility. However, the more precise
your exposure, the less you will have to compensate during the
developing and printing process.
The Zone System was developed by Ansel Adams and Fred Archer
as a simple and straightforward method by which they could control
exposure. Before Adams and Archer, the photographic industry
had already standardized f-stops and shutter speeds as controls
of light. But, those standards still left the photographer with
the question: "How much light must fall on the negative
in order to get the photograph I want?"
Adams and Archer took the spectrum of print values, from black
to white, and, using f-stops as the standard of measurement,
simply assigned a Zone to each value that each f-stop of exposure
produced. This results in a Zone Scale, which is a visual representation
of PRINT values from black to white. Zones are always represented
in Roman Numerals.
Keep in mind that light meters average the value of all light
they see. Based on that average they offer suggested settings
(f-stop/shutter speed combinations), all of which result in the
same exposure. That exposure is for a mid-gray Zone V.
A one-degree spot meter is advantageous as it allows you to read
a single small object from a distance, or, a small portion of
your overall scene.
Obviously, print values (from black to white) can be divided
into as many, or as few Zones as one wishes. However, eleven
is the standard by which most photographers work. This has the
advantage of placing the mid-gray Zone V, the meter reading,
in the middle of the scale. The Zones are numbered 0 through
X. Zone 0 represents the maximum black that the print can produce.
Zone X represents pure paper-base white - no image. The nine
zones between are each equivalent to one increasing f-stop of
exposure. Therefore, Zone III is lighter in value than Zone II,
and darker in value than Zone IV, etc.
It is at this point that some students become confused by assuming
that a Zone is a specific exposure. Not quite. A Zone is the
print value (tone) that will be produced when the film is properly
exposed and developed for that Zone. YOU determine the exposure,
the exposure determines the Zone you get. Your starting point
is the meter's suggested exposure for the value of Zone V.
Generic Zone scales are reproduced in most major technical books
on photography, and found in many magazine articles dealing with
the Zone System. However, the only truly accurate scales for
you will be the ones you may wish to make yourself, using your
personal equipment, films, etc.
The Zone scale is an 11-value gray scale. It can be helpful to
picture it in your mind, starting with the black step (Zone 0)
and progressing up to the pure paper base white step (Zone X).
With the known exposure to render your subject Zone V (the exposure
settings your meter will give you) you can adjust your exposure
to "place" the subject in any Zone desired, up or down
the scale. This helps you to previsualize the value you want,
and adjust the exposure to get it.
Let's review a few points before going further:
- The Zone scale is a progressive series of tone values,
each value being the equivalent of one full f-stop.
- The light meter provides exposure settings for Zone V,
giving you a correct exposure for a known Zone. That's your starting
point.
- By adjusting exposure you can place the subject in any
Zone, up or down the scale, from your starting point. The subject
will assume the tone value of the Zone in which it is placed.
Here is a brief description of each of the eleven zones.
0 - Black, no texture or detail.
I - Near black, no detail. Darkest beginning of gradation.
II - Dark gray-black, possibility of slight texture, you think
you see it - maybe. Mostly gradation.
III - Important Zone, very dark gray, but good texture and detail
can be seen. Dark textured bark on shadow side of tree. Where
you will probably want to "place" your shadow details.
Darkest detail and texture.
IV - Medium-dark gray, dark green foliage, shadow side of Caucasian
skin. Details plainly visible.
V - Your meter's suggested settings. Medium gray, Kodak
18% Gray Card, clear dark blue Northern sky, excellent detail
visible.
VI - Rich mid-tone gray, average Caucasian skin in sunlight,
shadowed snow on bright sunny day, sharp fine detail visible.
VII - Bright light gray, highest Zone that will still hold good
details. Weathered white paint, silver hair. VIII - Light gray-white,
shows last texture (minimum) but no detail. Reflected highlights
from light colored skin, textured snow in sun. Gradation exist.
IX - Almost white, must be compared to white to tell difference,
no detail or significant texture visible. Lightest gradation
values.
X - Reproduces as paper base white, no image recorded. In print,
will appear as specular highlights, sun reflection from chrome
bumper, sunlit drops of sparkling water, etc.
Lets go through the motions of using the Zone System.
Your camera is loaded, you have your spot meter, light, and an
egg. Meter the egg. Set your camera controls according to one
of the suggestions offered by the meter. Now, stop! Consider
what you are doing! The egg is off-white, it probably should
be a Zone VII in the photo, and that's how you want it. But,
the meter is giving you settings for a Zone V egg. You will have
to give the egg MORE exposure than indicated by the meter (more
light on the film, more light in the printed image.) Opening
the lens two f-stops from the suggested exposure will "place"
the egg in Zone VII.
Now grab that eggplant you just happen to have handy (as long
as we're on the subject of eggs). It's not black, but it's dark.
Maybe you would like to show it in the print as a Zone III. Again,
your meter gives exposure suggestions for a Zone V. By giving
two f-stops LESS exposure than indicated, the eggplant will be
placed in Zone III.
When changing exposure, you are establishing the tone values
in the finished print. In real life, the subject remains the
same. It is helpful to mentally visualize the changes in the
tone values of the print as you change exposure - moving up and
down the Zone scale.
In essence, you have just used the Zone System in its simplest
form. However, there are a few more things to cover.
Up to this point, our use of the Zone System has been limited
to a single object. In the real world, our scenes often have
many values.
Assume you are metering an outdoor scene. You see some good shadow
details you want to record, and you place them in Zone III. Now
you read your highest scene value and it's only a VII. If you
want it to be a VII, then shoot the scene, and that's what you
will get. On the other hand, what if you want that Zone VII to
be rendered a Zone IX?
That answer is the second part of the Zone System. We can also
control Zone placement (to an extent) by controlling development
of the negative.
Let's consider for a moment what happens to negative density
when we change developing time. As developing time is increased,
negative densities increase. But, highlight densities will increase
the fastest. Therefore, contrast also increases with increased
developing time.
Shadow density is controlled predominately by exposure.
Highlight density is controlled predominately by developing time.
Logic dictates that with additional developing time we will "overdevelop"
the highlights to push them up a Zone or two. Conversely, "underdevelopment"
will lower highlight densities, bringing them down a Zone or
two.
Per above, your highest scene value is Zone VII, and you want
it to be a IX. You can't stretch it with exposure, but you can
with development. A little additional development will NOT significantly
affect shadows, but will push highlights up the scale. Push them
up one Zone you have achieved Plus 1 development. This is referred
to as N+1, "normal development plus additional development
to achieve one additional Zone." N+2 implies two additional
Zones.
The reverse is also true. With lesser development, you can halt
the process before highlights mature. You can arrest development
while a potential Zone VIII has only reached a Zone VI. Again,
shadow areas will basically remain unchanged. This is called
Minus development, represented as N-2, indicating "normal
development time reduced the equivalent of two Zones." Plus
and Minus development is also referred to as "Expansion
and Contraction" development.
NOTE: Not all film/developer combinations will give the same
Plus/Minus control range.
With experimentation, you should be able to achieve at least
two Zones of highlight density change in each direction from
normal. Changes beyond that depend upon the particular combination
of materials you are using, and your techniques in handling them.
Keep in mind that with Plus or Minus development, you will also
be altering the contrast of your negative. The overall results
may prove perfect, or may require compensation during the printing
process.
"Fine", you say, "but I shoot rollfilm and cannot
develop each negative separately." Very true. The Zone System
was created with the use of cut film in mind. Each negative is
developed separately. So what of us who use rollfilm? There are
several workarounds, any one, or combination thereof, will help
get the job done.
Note that those who say the Zone System cannot work with rollfilm
are purists. They have not explored the real world. Obviously
they have lost sight of the fact that Adams also used a Hasselblad
with rollfilm, namely Tri-X Professional. The fact is, with a
little adaptation, the Zone System and rollfilm can live quite
happily together.
First, assume all negatives on a roll are developed to the same
degree. Negative contrast will then vary as original scene contrast
varies. In printing, low contrast scenes will be compensated
with higher contrast paper, and vise-versa.
Or, one could carry three cameras, each designated for Normal,
Plus, and Minus development. THREE cameras?
If Your budget allows, you may wish to consider one of the fine
cameras with interchangeable backs. One back can be designated
for each development.
I have two approaches to the matter. Ultimately, you will find
your own best solution. First, I can plan a day wherein my shooting
parameters will be very limited. I know where I am going, what
I will shoot, and, within reason, know the conditions will not
change - including the weather. Under these circumstances (and
if I stick to my guns) I should not have to worry about more
than one type of development. All negatives will be shot under
the same conditions.
When circumstances and conditions may vary, and I do not want
to miss any possibility, I take a very different approach. FILM
IS CHEAP! If I'm shooting scenes destined for normal development
and all of a sudden I run into a scene requiring Plus or Minus
development, I quickly jerk the film in the camera, mark it for
appropriate development, and reload. I am not about to miss a
great shot just to save a dollar's worth of film. To do so would
be penny-wise and pound foolish. If you use 35-mm film and are
so disposed, you can offset this minor cost by loading your own,
and always having some short (10 frame or so) rolls in your bag
destined for alternate development.
So, that's the Zone System. You now have a good start. From this
point you can continue to explore its nuances and technicalities
to your heart's content.
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