Find how many stops of light differ between two aperture values.
Each stop doubles or halves the light; a smaller f-number means a larger aperture opening and more light. Adding, subtracting and comparing aperture stops is the basic arithmetic of exposure control.
Stops Between Apertures
Stops = 2 x log2(apertureB / apertureA)
Stops = 2 x log2(apertureB / apertureA) Each stop doubles or halves the light; a smaller f-number means a larger aperture opening and more light.
Adding, subtracting and comparing aperture stops is the basic arithmetic of exposure control.
This calculator takes 2 inputs: Aperture A, Aperture B. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.