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

Exposure Factor

Required number input.

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

Additional Stops (stops)

The resulting additional stops 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.

• Bellows Extension Factor

  Exposure factor caused by lens extension when the lens-to-film distance exceeds focal length: (extension/focal)².

• Exposure Compensation

  Exposure-setting change in stops from current EV to desired EV; positive compensation means more light and therefore a lower desired EV.

• Exposure Triangle EV

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