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.

Distance Meters (m)

Required number input.

Flash f-number from guide number divided by flash-to-subject distance, 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]

F Number

The resulting f number returned as a number.

• Depth of field is a sharpness convention based on a selected circle of confusion, viewing size, distance, focal length, aperture, and focus distance. Diffraction, lens aberrations, sensor sampling, subject motion, and artistic tolerance are separate.
• 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 Distance

  Maximum flash-to-subject distance from guide number divided by f-number, 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.

• F Stop From Aperture

  F-number from lens focal length divided by entrance-pupil diameter.