The Zone System is a photographic technique invented by Ansel Adams and Fred Archer in 1941. At the time, most Photography was monochromatic and Adams worked out a system for visualization, which he considered to be a creative technique. He believed that you should look at a scene and visualize how you want the tones to look in the image. From that point he could apply exposure science to get the perfect exposure on film. Musicians say that if you can hum a tune, you can play it. Ansel Adams believed that if you could visualize the image you could photograph it. The Zone System provides photographers with a method of defining the relationship between the way they visualize the photographic subject and the final results. Although it originated with black and white film, the Zone System is also applicable to black and white and color, negative and reversal, and digital photography. The zone system is still taught today in photography schools and is a relevant tool for digital and film photography and for color and monochrome images. The image below is a good illustration of the zone system and you buy a print of this award winning image at my commercial gallery by clicking here.
The simple tool that Adams and Archer developed is this 11-point monochromatic strip ranging from Step 0 to Step 10. Adams and Archer discovered that the eleven zones could be corresponded to exposure values. Exposure values refer to the logarithmic relationship between Aperture, Shutter Speed and Sensitivity. Sensitivity is the film or sensors ability to record light. In his book “The Negative” published in 1948 Adams discusses the scientific relationship between exposure value and the Zone System allowing Photographers to calculate how to adjust exposure to compress or expand the zones. Again, this all ties into visualization and knowing how you want tones to be reproduced.
To aid Photographers in visualization, Adams developed descriptions for each Zone. Keep in mind that the zone system strip is positive but Adams was working with negatives. The pure black of Zone 0 means that the negative was completely clear. This guide is just as relevant today as it was 70 years ago in helping photographers visualize photographic situations. Knowing that a person with light skin is Zone VII and that my meter is balanced for Zone VI tells me I need to close down one stop to achieve the optimum exposure for their skin. Keep in mind light meters today are much more sophisticated then 70 years ago and it is important to understand the operation of your light meter. In any case a light meter will not help you visualize a scene but the zone system will.
Although the Zone System was developed for monochrome images it can be applied to color photography as well. Keep in mind that device independent color models like HSV are based on hue, saturation and value. Value refers to the light/dark part of the color and when combined with saturation control the density of the image. The logarithmic part of exposure value applies here and so does the zone system. The greater the value, the less detail will be displayed in the image. It is more complicated than monochrome for sure but not when applied to visualization. Try visualizing your subject in monochrome and apply the zone system to that visualization. Many photographers and cinematographers carry a viewer that subtracts color from the scene. This allows them to make initial lighting an exposure decisions before considering the color elements.