|The zone system is developed by Ansel Adams. Using the zone system Ansel Adams made very beautiful black and white prints. See SFMOma, for a Flash presentation of Ansel Adams‘ work (in honour of his hundreds birthday). Ansel Adams divided the gray gradations of a B & W print in 10 zones (each zone equals a stop from a light meter): starting at completely black (zone I) up until completely white (zone X). In the table below you will find a description of each zone. Already at the moment when you make a picture, the zone system helps you visualizing the final Black and White print. As an indication, we included for each zone the corresponding Luminance values in Photoshop. At the bottom of this page you will find some links where you can read some more about the zone system.|
Zone, or number ofstops:
Completely white, no structure, the colour of photopaper: snow in the sun (4 stops more)
White with structure: snow in the shadow (3 stops more)
|Light gray: very light skin tones. (2 stops more than according to camera)|
Gray tone of skin of a Westerner (1 stop more than according to light meter)
Average (18% gray card) gray: dark skin, weathered wood (lighting according to camera)
Average leaves, dark stone, shadow in landscape (1 stop less)
Darkest zone with clear structure. Dark subjects (2 stops less)
The beginning of structure in the shadows (3 stops less)
Almost black. No structure. (4 stops less than according to the exposure meter of the camera)
Completely black, no details at all
More about the zone system
In the section RAW, the difference between RAW (12 bit) and JPG (8 bit) files is illustrated using posterization. Another way to address the limitations of the 8-bit color space of the jpg file, or rather: the extra possibilities that a RAW file offers you is based on the above table for the zone system. Suppose you accidentally take a high key shot, of which the original contains many light tones (Zone IX and X, levels 205 to 255 in Photoshop) that you want to smear out over the entire tonal range (Zone I to X). If you would do this with a jpg shot, 50 levels would have to be divided over 255 levels in order to make of the high key shot a print with all shades of black to white again. You get a tone scale with abrupt transitions (“posterization”), because 50 levels are spread over a range of 255. The histogram shows 50 sharp lines instead of a continuous mountain landscape. With a RAW file, you would have to distribute 2048 gradations over 255 levels of the histogram. This produces a beautiful tone scale without abrupt transitions.
Photoshop plugins and Zone system software
More and more software appears for digital photography based on the zone system: LightZone is a special photo editing program (also for RAW files) based on the Zone System. For more information, see the discussion of LightZone on Digital Outback. Digital Film Tools offers a Photoshop plugin based on the zone system for 50 Euros: The program is called Ozone and on Digital Outback you can read a description of this Ozone plug-in (which can be used as a Smart Filter in Photoshop). The zone system is especially designed for black and white photography, but you also use the zone system with this plug-in with changes in color.