Zone-system Calculation For Photographic Exposures
| Field | Photography, particularly (though not exclusively) black and white film photography |
| Went Obsolete | Began to be obsoleted in the 1970s when cameras with automatic exposure systems began to be available |
| Made Obsolete By | The Minolta XK SLR in 1972 was (possibly) the first SLR with an automatic exposure system |
| Knowledge Assumed | The Zone system is a way to visualize a scene in terms of 10 levels of illumination from pure black to pure white |
| When useful | Used to make photographs containing a full range of illumination |
The Zone System, invented by Fred Archer and Ansel Adams in the 1940s, was originally intended as a way to improve the range of luminance represented in black-and-white film photography. Adams' photographic landscapes are famous for their dynamic range; blacks are true blacks, and white objects are completely white. The Zone-system photographer uses a light meter to determine the luminance of individual items in the scene, including an object or surface that should be rendered in the print as true white (zone 10), another that should be true black (zone 1), and so forth.
Information about the Zone system is available at Wikipedia. Sample public-domain images by Ansel Adams are available at Wikicommons.
The Zone System includes not just the exposure of the light hitting the subject but also how the negative will react to said exposure. Are there any expansions or contractions required when processing the negative to aid in the final printing of the image. Will the toe (black) and shoulder (white) be compatible with the paper chosen. Finally how much manipulation will be needed (burning and dodging) to bring out all 10 zones in the final print.
Zone System Photography is well beyond the grasp of most photographers due to the need of individual exposures of negatives. Roll film will not cut it here and only large format or small “speed” cameras (sheet film 2 1/4 inch size) will do. If you end up with an image with all your detail in shadows and highlight details in other areas you may need to over expose and then under process to even out said details. Doing this you will be able to print on a lower contrast paper or use less manipulation to get the details you want. On a roll camera you may be able to process the roll normal and then highly manipulate the print (burn, dodge, use multiple contrast filters while burning (with multiple contrast papers only)) to get a usable print. In the end it may not be on a paper surface or tone you really wanted.
Zone System never fell from usage. It was never that popular because it was never in the “Joe Public” realm to begin with. Large camera's using 4”x5” film to start with; all the over sized, over weight, and over priced equipment that goes with it, never made it “popular”. BUT…being able to visualize a scene, know how your film reacts to those light levels, be able to manipulate the exposure and process for the details for the paper you want to use, put you in a rarefied level in photography not known by many…
