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

Guide Number Meters (m)

Required number input.

F Number

Required number input.

Maximum flash-to-subject distance from guide number divided by f-number, at the guide number's ISO and flash setting. 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]

Distance Meters (m)

The resulting distance meters 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.

• Guide Number Aperture

  Flash f-number from guide number divided by flash-to-subject distance, at the guide number's ISO and flash setting.

• Aperture From F Stop

  Entrance-pupil diameter from focal length divided by f-number; not the physical diaphragm diameter.

• Depth Of Field

  Finite depth of field from focal length, f-number, circle of confusion and focus distance using thin-lens near/far limits.