Equivalent exposures
Open the aperture one stop and halve the shutter and the brightness stays the same. Enter a metered setting to see every equivalent pair, so you can choose depth of field or motion freely.
Wider apertures blur the background and need a faster shutter; smaller apertures deepen focus and need a slower one. All rows below give the same exposure.
About this tool
Open the aperture a stop and halve the shutter and the brightness stays the same. Enter a metered aperture and shutter, and this lists every equivalent pair, so you can trade depth of field for a faster shutter without changing the exposure.
How to use it
- Choose your metered aperture.
- Enter the metered shutter speed.
- Read the table of equivalent aperture and shutter pairs.
- Pick the pair that gives the depth of field or motion you want.
FAQ
Why are these all the same exposure?
Each step wider in aperture doubles the light, so halving the shutter cancels it out; every row lets in the same total light.
Which pair should I pick?
Wide apertures for a blurred background and fast action, small apertures for front-to-back sharpness.