Crop Factor Calculator — Equivalent Focal Length & Aperture

Crop factor is the ratio of the full-frame sensor diagonal (43.27mm) to your sensor diagonal. APS-C sensors have crop factors of 1.5x (Nikon/Sony) or 1.6x (Canon). It determines how much the field of view is narrowed compared to full frame. A 50mm lens on a 1.5x crop sensor gives the same field of view as a 75mm lens on full frame.

No. A 50mm lens is always 50mm regardless of sensor size. Crop factor only affects the field of view — the sensor captures a smaller portion of the image circle. The focal length, aperture, optical quality and perspective remain the same. Only the framing changes.

When comparing depth of field between sensor sizes, you multiply the aperture by the crop factor. A 50mm f/1.8 on APS-C (1.5×) gives similar depth of field to 75mm f/2.7 on full frame (1.8 × 1.5 = 2.7). This does NOT affect exposure — f/1.8 lets in the same amount of light per unit area on any sensor, so shutter speed and ISO are unchanged.

Yes. Medium format sensors are larger than full frame, so their crop factor is less than 1. The Fuji GFX system has a crop factor of about 0.79x. A 63mm lens on GFX gives the same FOV as a 50mm on full frame, but with shallower depth of field.