The Zone System (ZS) can be an integral and important part of any digital photographer’s workflow because it allows you to plan and predict an image’s tonal values rather than letting the camera make the decision. The computerized metering systems in modern cameras are really amazing, and a lot of the time they will give you practical exposures, but in difficult or extreme lighting situations, the scale of the subject’s brightness is simply greater than the camera’s technology can handle.
The Zone System:
- Lets you be aware of whether, or how much, the scene brightness exceeds your camera’s limits
- Lets you make an intelligent decision about how to expose when the tones/contrast in a scene are “bigger” than what your camera can capture
- Helps you avoid blown-out highlights
- Lets you know how much exposure range you need for successful HDR captures
The Zone System 101
To use the Zone System effectively in the digital world, you need to understand a few of its basic principles: The ZS was originally conceived by Ansel Adams and fellow photo instructor Fred Archer as a tool to give photographers working with black-and-white negative film (no digital back then!) the ability to plan and control the effects of exposure and development. They created a “scale” of tones from black to white and assigned each one a number, with “I” being almost pure black and “IX” or “X” being nearly white or white. Zone “V” is middle gray, and each “Zone” is one stop lighter or darker than its neighbor. In the digital age, image contrast can be easily increased post-capture, but there is no practical means of reducing image contrast in a single capture. Pre-exposure can enhance shadow tonality, but this requires the ability to double-expose, and High Dynamic Range techniques (HDR) require three or more exposures for best results. Sophisticated “evaluative” metering modes in modern cameras can handle many complicated shooting situations, but if the contrast of the scene exceeds the recording scale of the camera, something’s gotta give. This is where the ZS can help……..