crop factor

A 1.5x or 1.6x APS-C sensor sees the same field of view as a lens 1.5 or 1.6 times longer on full frame, so a 300mm frames like a 450mm. Nothing about the lens changes — it is the same optic projecting the same image and the sensor simply records less of it — but for a spotter who never has enough reach, that narrower view is a real advantage.

Nearby in Photography

• chromatic aberration — Coloured fringing caused by a lens focusing different wavelengths at slightly different points.
• clipping — Loss of detail where tones exceed what the sensor or file can record, leaving pure white or pure black.
• crop sensor — A sensor smaller than a 35mm frame, most commonly APS-C at around 24 by 16 millimetres.
• depth of field — The range of distances that appear acceptably sharp in an image.