The F16 rule is not a regulation for the Lochhead Fighting Falcon but a basic light estimation method.
Commonly known as the Sunny f16 rule (also known as the Sunny f/16 rule) it can achieve correct exposure of difficult subjects. As the rule is based on incident light, rather than reflected light as with most camera light meters, very bright or very dark subjects are compensated for. The rule serves as a mnemonic for the camera settings obtained on a sunny day using the exposure value (EV) ...