Equivalent Exposure Calculatorv1.0.0

Maintain the same overall exposure when changing camera settings. Photographic exposure is controlled by three variables: aperture (f-stop), shutter speed, and ISO sensitivity. Changing one variable affects the light captured, and a compensating change in another can produce an identical exposure. Find those compensating values quickly without manual log calculations.

• Set your current camera settings under Exposure A (Reference) by selecting values for Aperture, Shutter Speed, and ISO.
• Set different values under Exposure B (Adjusted) to compare two exposures. The calculator displays the EV (Exposure Value) for each setting and the difference between them in stops.
• To find an equivalent exposure, choose which parameter to adjust under Find Equivalent Exposure. Select Adjust shutter speed for aperture priority, Adjust aperture for shutter priority, or Adjust ISO for manual mode. Click Find Equivalent Exposure to set Exposure B so it matches the light captured by Exposure A.
• To apply exposure compensation, enter an EV offset in the EV Compensation field. Decimals (1.33), fractions (2/3), mixed numbers (1 1/3), and negatives (-2/3) are accepted. Click Apply Compensation to B to shift Exposure B by that many stops.
• Open Settings to enable a step-by-step EV derivation, or to switch dropdown granularity between 1/3 stop, 1/2 stop, and full stop increments.
• The EV formula is EV = log base 2 of (f-number squared divided by shutter duration in seconds). Light Value normalizes the exposure to ISO 100 for cross-comparison across different sensitivity settings.
• All settings persist in browser local storage. Click Reset to restore defaults. Share configurations by bookmarking the URL with query parameters.

Photographers at every skill level benefit from understanding equivalent exposures. Whether planning a shoot, troubleshooting exposure in the field, or learning the exposure triangle, the calculator provides instant feedback and educational value.

• Landscape Photography: Determine how to use a smaller aperture like f/16 for maximum depth of field while compensating with a longer shutter speed. Enter a current exposure at f/5.6 and find the equivalent shutter speed at f/16 to maintain identical brightness.
• Sports and Action Photography: Calculate the ISO increase needed when switching from 1/250 second to 1/2000 second to freeze fast motion while keeping the same aperture and exposure level.
• Low Light and Night Photography: Compare a 30-second exposure at ISO 800 with shorter alternatives at higher ISO values to evaluate noise trade-offs while maintaining equivalent exposure.
• Studio Photography: When adjusting strobe power or changing modifiers, use the compensation feature to determine how many stops of camera adjustment are needed.
• Education and Learning: Students studying the exposure triangle can experiment with combinations and review the step-by-step EV derivation to understand how aperture, shutter speed, and ISO relate mathematically.
• Neutral Density Filter Use: After attaching an ND filter rated at a specific stop reduction, apply that value as negative EV compensation to find the new shutter speed or aperture needed.
• Astrophotography: Compare exposures for star trails versus tracked shots, determining how ISO and shutter speed changes affect total light gathered while staying within star trailing limits.
• Video Production: Find equivalent exposures when locked to specific shutter speeds (such as 1/50 second for 25fps or 1/48 second for 24fps) and aperture or ISO needs to match a target exposure.