Crop Factor
Calculator
Results
- Equivalent focal length
- 52.5
Media and photography results
| Equivalent focal length | 52.5 |
formula-map diagram
- Equivalent focal length
- 52.5
Media and photography relationship
Formula
f_eq = f × crop= 52.5
Note
This result uses the values you entered and a simplified planning equation; verify quantities and local requirements before purchasing or building.
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See all →Frequently asked questions
What does crop factor actually represent?+
Crop factor is the ratio between a full-frame sensor's diagonal and a smaller sensor's diagonal, expressing how much 'tighter' the smaller sensor's field of view is at the same focal length. An APS-C sensor with a 1.5x crop factor captures a field of view equivalent to 1.5 times the focal length on full-frame.
Why do people talk about a lens's 'effective focal length' on a crop sensor?+
A 50mm lens is still physically a 50mm lens regardless of sensor, but on a 1.5x crop sensor it produces a field of view matching what a 75mm lens would show on full-frame, so photographers describe it as having a '75mm equivalent' field of view for comparison purposes, even though the actual optical focal length hasn't changed.
Does crop factor affect only field of view, or does it change depth of field too?+
Crop factor directly changes only the field of view, but because achieving the same framing on a cropped sensor requires either a shorter focal length or standing farther back, it indirectly results in a different depth of field for an equivalent composition, generally deeper depth of field on smaller sensors for the same framed shot. This is a secondary effect, not a direct property of crop factor itself.
Why does crop factor not actually change a lens's true focal length or aperture?+
The lens's physical optical properties, its true focal length and its actual light-gathering aperture, are fixed by its construction, so crop factor is purely a framing/field-of-view comparison tool describing how a smaller sensor 'sees' less of the same image circle. This is why exposure settings (aperture, shutter, ISO) don't need adjustment for crop factor, only your sense of framing does.
How is crop factor useful when buying a lens for a specific camera?+
Knowing your camera's crop factor lets you predict what field of view a lens will actually deliver before buying it, which matters especially for wide-angle work, since a 16mm lens behaves like a 24mm on a 1.5x crop body, potentially not wide enough for the intended use. This calculation avoids surprises when moving a lens between full-frame and crop bodies.