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

Focal Length Millimeters (mm)

Required number input.

F Number

Required number input.

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

Entrance Pupil Millimeters (mm)

The resulting entrance pupil millimeters 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.

• F Stop From Aperture

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

• 35mm Equivalent Focal Length

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

• Circle Of Confusion

  Conventional permissible circle-of-confusion diameter from sensor diagonal divided by a user-selected viewing divisor; not an optical constant.