Photography & Imaging

Basic

Equivalent Focal Length

Focal length on a crop sensor expressed in full-frame terms.

Formula

f_{eq} = f \times C

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Variables

f_{eq}Equivalent focal length (mm)

fActual focal length (mm)

CCrop factor

Example

35 mm lens, 1.6× crop: f_eq = 56 mm

Did You Know?

An APS-C sensor's 1.5–1.6× crop factor turns a cheap 50 mm into a portrait-friendly ~80 mm.

photography crop factor sensor

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More in Photography & Imaging

F-Number

Aperture f-number is focal length divided by aperture diameter.

Exposure Value (EV)

Combines aperture and shutter speed into one exposure figure.

Depth of Field (approx.)

Range of distances that appear acceptably sharp.

Hyperfocal Distance

Focus distance that keeps everything from H/2 to infinity sharp.

Lens Magnification

Image magnification from focal length and subject distance.

Angle of View

Field of view from sensor size and focal length.