Shutter Reciprocity
Find a new shutter speed that changes exposure by a chosen number of stops.
About Shutter Reciprocity
Each positive stop doubles the shutter denominator, halving the light and freezing more motion, while negative stops lengthen the exposure. Reciprocity lets you trade aperture, ISO and shutter freely to keep the same total exposure for a creative look.
Formula
Shutter Reciprocity
New shutter = base x 2^stops
- stops of change
- Positive means a faster shutter, negative slower
Worked example
With the default values below, Shutter Reciprocity returns New Shutter (1/x s) of 500. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Base shutter (1/x s)minimum 1
- 125
- Stops of changeaccepts -6–6
- 2
Results
- New Shutter (1/x s)
- 500
- New Shutter in Seconds
- 0.0020
- Effect
- Faster shutter (less light)
Step by step
- 1Values used
- 2Shutter Reciprocity
- 3New Shutter (1/x s)= 500
- 4New Shutter in Seconds= 0.0020
- 5Effect= Faster shutter (less light)
Assumptions and limits
- The result is derived only from the 2 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Shutter Reciprocity calculated?
New shutter = base x 2^stops Each positive stop doubles the shutter denominator, halving the light and freezing more motion, while negative stops lengthen the exposure.
Why does Shutter Reciprocity matter?
Reciprocity lets you trade aperture, ISO and shutter freely to keep the same total exposure for a creative look.
What values do I need to enter?
This calculator takes 2 inputs: Base shutter (1/x s), Stops of change. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.