Aperture f/16 use shutter speed of 1 over ISO on a bright sunny day, that’s the basic jist of the Sunny 16 Rule. Conditions Settings Sunny ISO 100 f/16 1/100s Slight Overcast ISO 100 f/11 1/100s Overcast ISO 100 f/8 1/100s Heavy Overcast ISO 100 f/5.6 1/100s Shade ISO 100 f/4 1/100s Back in the …