Crop Factor

Focal Length & Crop Factor Calculator

Compare how prime and zoom lenses frame the same scene across different camera sensors.

Example scene: Den Haag Skyline
  • Lens A: 50mm
  • Lens B: 52.5mm
Lens A
Prime
Focal length
Sensor
Full frame · 1×

Sony α7, Nikon Z6/Z8, Canon EOS R, Panasonic S, Leica SL

Effective50mm × 1
50mm
Lens B
Prime
Focal length
Sensor
APS-C · 1.5×

Sony α6000 series, Nikon Z50/Zfc, Fujifilm X-series

Effective35mm × 1.5
52.5mm
Effective = focal length × crop factor

Where your lenses land

Lens A: 50mm full-frame equivalent
Lens B: 52.5mm full-frame equivalent
Architecture, ≤35mm: no lens
Landscape, 14–50mm: covered by Lens A
Street, 24–50mm: covered by Lens A
Travel, 24–85mm: covered by Lens A, Lens B
Portrait, 50–135mm: covered by Lens A, Lens B
Wildlife, 135mm+: no lens
Full-frame equivalent · log scale

The basics, in a minute

Calculators by sensor

APS-C calculator Compare Nikon/Sony/Fuji with Canon 1.6×. Full frame vs. APS-C Match fields of view across formats. Micro Four Thirds Convert lenses with the 2× crop factor.

Photography Basics: Understanding Your Camera Lens

What is Focal Length?

Think of focal length like your camera's "zoom level." It's measured in millimeters (mm), and it tells you how wide or zoomed-in your photo will be:

  • Small numbers (like 24mm) = Very wide view, like what you'd use to photograph a large building or a landscape
  • Medium numbers (like 50mm) = Natural view, similar to what your eyes see
  • Large numbers (like 200mm) = Zoomed in view, perfect for wildlife or sports photography

(For the technically curious: focal length is the distance between your camera's sensor and the optical center of the lens when focused at infinity.)

What is Crop Factor?

Different cameras have different-sized sensors (the digital equivalent of film). Crop factor tells you how your camera's sensor size affects your photos compared to a traditional full-frame camera:

  • Full-frame cameras (crop factor = 1.0x): These are like traditional 35mm film cameras - what you see is what you get
  • Most consumer cameras (crop factor = 1.5x or 1.6x): These include many popular Canon, Nikon, and Sony cameras. They make your lens appear more zoomed in
  • Micro Four Thirds cameras (crop factor = 2.0x): These cameras, like Olympus and Panasonic, make your lens appear twice as zoomed in

Think of crop factor like a digital zoom - it makes everything appear closer without actually changing your lens.

What is Effective Focal Length?

Effective focal length helps you understand how your photos will actually look based on both your lens and your camera's sensor size. It's simple:

The Simple Way: Multiply your lens number by your camera's crop factor

Real-World Example: If you're using a 50mm lens on a typical consumer camera (1.5x crop):
50mm × 1.5 = 75mm effective focal length
This means your photos will look like they were taken with a 75mm lens on a full-frame camera!

What is Field of View (FOV)?

Field of view is simply how much of the scene your camera can see - like how much you can see through a window. A bigger window (wider field of view) lets you see more of the scene.

Remember:

  • Longer focal length = narrower field of view (like looking through a telescope)
  • Shorter focal length = wider field of view (like looking through a big window)
  • Larger crop factor = narrower field of view (like zooming in digitally)