Focal Length Calculator
Calculate equivalent focal lengths across different sensor sizes. Understand how crop factor affects field of view when comparing full-frame, APS-C, and Micro Four Thirds cameras.
Focal Length Calculator
Calculate equivalent focal lengths across different sensor sizes
Common Focal Lengths
Formula
Equivalent FL = Actual FL × Crop FactorConvert focal lengths between sensor formats to understand field of view equivalence
How to Use
- 1Enter focal length — Input your lens focal length in millimeters.
- 2Select your sensor — Choose your camera's sensor format.
- 3Select comparison — Choose the sensor format to compare against.
- 4View equivalents — See the equivalent focal length and field of view.
Frequently Asked Questions
What is crop factor?
Crop factor is the ratio of a camera sensor's diagonal to a full-frame (35mm) sensor. APS-C has a 1.5× crop factor, meaning a 50mm lens gives the same field of view as a 75mm lens on full-frame.
Does crop factor affect depth of field?
Indirectly, yes. To get the same field of view on a crop sensor, you use a shorter focal length, which increases depth of field. A 35mm lens on APS-C gives similar framing to 50mm on full-frame, but with more depth of field.
What is 35mm equivalent?
The 35mm equivalent is the focal length that would give the same field of view on a full-frame (35mm) camera. It's a standard reference point for comparing lenses across different sensor sizes.
Why do different APS-C cameras have different crop factors?
Canon APS-C sensors are slightly smaller (1.6× crop) than Nikon/Sony/Fuji APS-C sensors (1.5× crop). This small difference affects equivalent focal length calculations.
How does sensor size affect image quality?
Larger sensors generally capture more light, providing better low-light performance and dynamic range. However, modern smaller sensors have improved significantly, and the difference is less pronounced than before.