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Equivalent Exposure Calculator
New shutter speed that keeps exposure the same after changing aperture or ISO.
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1/s
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How it works
Exposure stays constant when ISO × time ÷ N² stays constant. So new time = old time × (new N² ÷ old N²) × (old ISO ÷ new ISO). Opening the aperture by one stop lets you halve the shutter time, and raising ISO by one stop does the same. This is the same trade-off every photographer makes when freezing motion or controlling depth of field. Example: Opening up from f/8 to f/4 at ISO 100 turns 1/125 s into 1/500 s, a change of 2 stops of aperture.
FAQ
Is this calculator free?
Yes. No signup is needed and nothing you enter is stored.
Is the result exact?
Results are rounded for display. For financial, medical, or legal decisions, confirm with a professional.
Do my numbers leave my device?
No. The calculation runs in your browser.