Ansel Adams Zone System - Zone Definitions

When testing your film, Zone I exposure is used to determine the 'speed point' which is used to test for your personal Exposure Index or E.I. (the true ISO for the film you use). The true ISO, your personal E.I., is obtained when a Zone I exposure produces a density between 0.08 and 0.15 above film base plus fog. This is the bottom of the toe of the characteristic curve. (See Film Tests for more info.)

A Zone I exposure is four stops less than your light meter indicates for the area of the subject measured.

Zone II exposure is the first level of exposure that records useful detail on the film. This produces a very dark tone in a print that has the slightest hint of texture in it. The amount of texture alone would not be enough to accurately identify the subject. This tone in a print gives depth to the shadow areas without looking completely blocked in.

This is the darkest zone of the texture range (The range of zones that provide visual detail and texture).

To obtain a Zone II exposure for an area of the subject, reduce the indicated meter reading from the area by three stops.

Zone III is the first level of exposure that produces full detail on the film. In the print, a Zone III exposure of the film produces a tone that is dark but with excellent texture. The subject would be identifiable from the texture. If you want good detail in a shadow, it must receive at least a Zone III exposure on the film.

This is the darkest tone that contains full detail. This is a very important zone!

To obtain a Zone III exposure for an area of the subject, reduce the indicated meter reading from the area by two stops.

Zone IV is a shadow that is full of detail and looks full of light. It is one stop less exposure than the light meter indicates. It is the print tone you would normally experience on the shadowed side of a strong portrait or the shadows of a front lit building in sunlight.

To obtain a Zone IV exposure for an area of the subject, reduce the indicated meter reading from the area by one stop.

Zone V represents 'middle grey', an 18% reflectance equivalent to the Kodak Grey Card. Middle grey is generally the lightest 'shadow' tone and is seen on a print as a very luminous shadow. Zone V could be the shadow on the face of a portrait with low contrast lighting, e.g 3:1. When you use a light meter to measure an area of the subject, the reading indicated by the meter is designed to reproduce that area as a middle grey. Simply remember that a light meter always indicates a Zone V exposure. If you require a different exposure zone, you must modify the meter reading.

Examples of subjects that usually (remember these are recommendations not rules) require Zone V exposure are, clear blue north sky, green grass in sunlight, dark skin, grey stone, average weathered wood.

Zone VI represents a well lit subject with full detail. It is usually the lightest of the middle values of the subject. It helps to understand the last statement if you remember to visualise the grey scale in three parts, Zones O to III are low values (dark areas), Zones IV to VI are middle values (where most detail is seen) and Zones VII to X are high values (light areas). Examples of Zone VI would be Caucasian skin tones in sunlight or diffuse daylight, light stone, shadows on sunlit snow.

To obtain a Zone VI exposure for an area of the subject, increase the indicated meter reading from the area by one stop.

Zone VII represents a light area that still retains excellent detail. Examples would be very light skin, side lit snow, light coloured or grey objects. Think of a Zone VII exposure as producing a 'bright' print tone.

To obtain a Zone VII exposure for an area of the subject, increase the indicated meter reading from the area by two stops.

Zone VIII is a very important zone because it represents the 'film development point' and is the last high value zone that will contain good texture. Examples of a Zone VIII exposure would be whites with texture (white sweater, white painted wood), textured snow, the highlight on the cheek of a Caucasian face.

This is the lightest zone in the texture range.

Zone VIII is used when testing the development of a monochrome film. For correct development to produce negatives for use with diffuse light enlargers, the density produced for a Zone VIII exposure should be in the range 1.25 to 1.35 above base plus fog. (See Film Tests for more info.)

To obtain a Zone VIII exposure for an area of the subject, increase the indicated meter reading from the area by three stops.

Zone IX exposure produces the lightest tone on the print before pure paper white. This tone will not retain detail, it adds subtlety and beauty to the high values of a print but does not show detail. This is similar to what Zone I does for the dark areas.

Examples would be flat white paper, textureless white paint, snow in flat sunlight.

This is the lightest zone in the dynamic range.

To obtain a Zone IX exposure for an area of the subject, increase the indicated meter reading from the area by four stops.

Zone X exposure represents the pure white of the print paper. Anything on or above Zone X is blank white in the print. This cannot be printed down to obtain detail, the detail is so compressed that it will not separate in the print! This is the top of the shoulder of the 'traditional' characteristic curve (many modern films do not show a shoulder on the characteristic curve until much more exposure is received, but our restriction is still the print paper!). Like Zone O, if it ain't on the film, it can't be on the print!

To obtain a Zone X exposure for an area of the subject, increase the indicated meter reading from the area by five stops.