The Sunny Sixteen Rule.

What is the ‘Sunny Sixteen Rule?

Short answer is, the easiest way to calculate exposure without using a light meter.

We touched on using the Sunny Sixteen Rule in our review on 135mm lenses, please allow me to elaborate.

How the ‘Rule’ works.

ISO set equals the shutter speed set, intensity of daylight dictates the aperture used – ie. bright sun means an aperture of f16. (Hence Sunny Sixteen)

The full list goes like this:

The above figures are not hard and fast rules, if you are photographing in extremely bright conditions, such as snow or on a beach the shutter speed will need to be increased or a smaller aperture used. Additionally there may be a preference to use a faster or slower shutter speed or larger or smaller aperture, this just means recalculating, all the figures are linear. For example – 100 ISO with bright sun and hard shadows using a shutter speed of 1/200th sec would use an aperture of f11.

The Sunny Sixteen Rule harks back to the days of film photography when most cameras were totally manual, a lot of film boxes even to this day still have an exposure guide printed on the inside.

The last film cameras and all digital cameras have very advanced light meters built in and usually if the meter is not functioning, then there may be problems beyond just a meter malfunction. In saying this, the Sunny Sixteen Rule can be applied as a rough guide if you doubt the reading your meter is giving.

As an experiment, try using the rule and compare with your camera’s built in meter.

Colin