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

F Number

Required number input.

Shutter Seconds (s)

Required number input.

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

Ev100 (EV)

The resulting ev100 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)].

• Shutter Efficiency

  Measured shutter efficiency percentage from actual open time divided by commanded exposure time.

• Bellows Exposure Compensation

  Additional exposure in stops from a measured bellows exposure factor: log₂(factor).