Use this cinematography or projection calculation to plan image geometry, exposure, timing, storage, film footage, or presentation from explicitly stated camera and display parameters.

Base Iso

Required number input.

Target Iso

Required number input.

Analog-equivalent ISO gain change in decibels as 20 log₁₀(target ISO/base ISO); a doubling corresponds to about 6.02 dB. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Gain Decibels (dB)

The resulting gain decibels returned as a number.

• Exposure arithmetic assumes calibrated ISO, aperture, shutter, flash guide number, and filter density conventions. Lens transmission, reciprocity failure, bellows factors, flash zoom, ambient balance, metering bias, and clipping can alter the practical setting.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Confirm critical values with the actual camera, lens, codec, projector, and delivery specification, then run a camera or projection test under representative conditions.

• Exposure Triangle EV

  ISO-adjusted exposure value referred to ISO 100: log₂[(N²/t)(100/ISO)].

• Exposure Value EV

  Exposure value at ISO 100, EV=log₂(N²/t), from f-number N and shutter time t in seconds.

• 35mm Equivalent Focal Length

  35 mm full-frame-equivalent focal length using the 36×24 mm diagonal divided by the camera sensor diagonal.