LESSON 68
The zone system
Placing tones on purpose, from black to white.
IN THIS LESSON
- What it is
- Eleven zones, one stop apart
- Place and fall
- In practice: on a digital camera
What it is
The zone system is a method for deciding film exposure and development so that the final print shows the tones you imagined. It was formulated by Ansel Adams and Fred Archer around 1939 to 1940 at the Art Center School in Los Angeles. Adams described it as a codification of the science of sensitometry rather than an invention, building on studies by Hurter and Driffield in the late nineteenth century. It began with black and white sheet film, but the source notes it applies to roll film, colour, slides and digital too. Imagining the final picture before you expose is called visualisation.
Eleven zones, one stop apart
The system numbers tones from 0 to 10, written in Roman numerals: Zone 0 is black, Zone V is middle grey and Zone X is pure white. Each zone differs from its neighbour by a factor of two, so one zone equals one stop. A meter always tries to render what it reads as Zone V. A photographer knows that fresh snow and a black horse are not middle grey, and can place them where they belong. Adams also named narrower ranges: Zones I to IX as the useful range of a negative, and Zones II to VIII as the range that shows texture and substance.
Place and fall
The basic move is simple. Spot meter one important area, decide which zone it should be, and adjust the exposure from the meter's reading by that many stops. If you meter a dark rock and want it in Zone III, give two stops less than the meter suggests. Other tones then fall wherever they fall, a fixed number of stops above or below. In film work the photographer then adjusts development to expand or compress the range of the negative, so the highlights land where the print needs them. Because practical development differs from the standard, practitioners usually test their own effective film speed, often based on Zone I.
In practice: on a digital camera
This section is working practice. On a digital camera the idea becomes exposing to protect the highlights you care about. Spot meter the brightest area that must keep detail, such as a white wall in sun, and place it at about Zone VII, roughly two stops over the meter's reading. Check the histogram and the highlight warning, then lift shadows in the edit if needed. Learn your own sensor: shoot a white card at one stop steps above the meter and see where detail disappears. That number is your personal top zone.
| Zone | Tone | Example in the print (practice) |
|---|---|---|
| 0 | pure black | no detail at all |
| III | textured dark | dark fabric with visible weave |
| V | middle grey | what the meter assumes |
| VII | textured light | light skin or pale stone with detail |
| X | paper white | no detail at all |
Try it today
- 01Set spot metering and manual exposure.
- 02Meter a white surface in sun and shoot it at 0, +1, +2 and +3 stops from the reading.
- 03Note where texture disappears; that is your highest useful zone.
- 04Meter a dark surface and shoot at 0, -1, -2 and -3 stops.
- 05Photograph a real scene by placing one key tone, and let the rest fall.