Sunny 16 Rule notes

In it’s simplest form, the Sunny 16 rule (or Sunny F/16 rule) states: On a bright, sunny day, the correct exposure for any middle tone subject is F/16 at the shutter speed nearest to the reciprocal of the film speed. For example:

ISO 100 = 1/100 second @ F/16

ISO 200 = 1/200 second @ F/16

ISO 400 = 1/400 second @ F/16

ISO 800 = 1/800 second @ F/16

equivalent exposer different settings same exposer of light