Camera Controls - Sunny 16 Rule

In photography, the Sunny 16 Rule is a method of setting correct daylight exposures without using a light meter.

The formula for the Sunny 16 Rule is:  ISO 100  +   f/16   +  1/125   =  perfect exposure

Setting the camera to Manual and using these settings will correctly record your subjects that are located in bright sunlight, whether using film or digital capture.

Most cameras rely upon reflected light for estimating the exposure. Reflected light exposures can cause very bright subjects to be recorded as too dark and very dark subjects to be recorded as too light. The Sunny 16 Rule is based upon incident light which will record very bright or very dark subjects correctly.

The Sunny 16 Rule can be adjusted for other apertures:

ISO 100  +   f/22   +  1/60   =  perfect exposure

ISO 100  +   f/16   +  1/125   =  perfect exposure

ISO 100  +   f/11   +  1/250   =  perfect exposure

ISO 100  +   f/8   +  1/500   =  perfect exposure

ISO 100  +   f/5.6   +  1/1000   =  perfect exposure

ISO 100  +   f/4   +  1/2000   =  perfect exposure

The Sunny 16 Rule can be modified for other ISO settings:

ISO 200  +   f/22   +  1/125   =  perfect exposure
OR
ISO 200  +   f/16   +  1/250   =  perfect exposure

ISO 400  +   f/32   +  1/125   =  perfect exposure
OR
ISO 400  +   f/16   +  1/500   =  perfect exposure

...and so on.

For lunar photography there is a similar rule known as the Looney 11 or Lunar 11 rule; simply substitute f/11 for perfect exposures of the moon.