1/ISO Quick Tip (Sunny 16 Rule)
Monday quick tip! In general, you can be assured to capture a properly exposed image at mid day with the rule 1/ASA.
Mid Day Sun aperture @ f/16 = shutter @ 1/ISO
So if your ISO is set to 100, you would have a shutter speed of 1/125 at f/16 for optimal exposure in mid day sun. Because there is no shutter speed exactly 100 set it to the next closest value (in my example 125).
With this rule in mind you simply need to change your ISO and/or Shutter one stop for each one stop of aperture you change to create the depth of field you desire.
For example if you want a shallow depth of field and change your aperture to f/4 (4 stops of light = f/16, f/11, f/8, f/5.6, f/4) then you would increase your shutter speed by 4 stops as well from 1/125 to 1/2000 (1/250, 1/500, 1/1000, 1/2000).
Use the same rule for different light conditions:
f/16 – Full Sun
f/11 – Slightly overcast
f/8 – Overcast
f/5.6 – Heavy overcast.