Crop Factortechnical
How much a smaller sensor 'crops' the view vs full-frame — multiplies your effective focal length.
See it
Drag to see the effect (illustrative simulation).
Full frameAPS-C (1.5×)APS-C (1.6×)MFT (2.0×)
A 50mm lens frames like…50mm
A sensor smaller than full-frame sees a narrower slice of the scene. Multiply the lens focal length by the crop factor for the full-frame-equivalent reach: a 400mm lens on a 1.6x Canon APS-C frames like 640mm. Great for wildlife reach, but the wider end gets less wide, and depth of field looks deeper for the same framing.
Use this when
- Canon APS-C: 1.6x
- Nikon/Sony APS-C: 1.5x
- Micro Four Thirds: 2.0x
Common mistake: Expecting a 16mm lens to stay ultra-wide on a crop body — it frames like ~24mm.