Focal length
Your lens's zoom level in mm. Small numbers see wide, big numbers see close.
Read more about focal length →Crop factor & equivalent focal length calculator — compare any lens on any sensor.

Sony α7, Nikon Z6/Z8, Canon EOS R, Panasonic S, Leica SL
Sony α6000 series, Nikon Z50/Zfc, Fujifilm X-series
Your lens's zoom level in mm. Small numbers see wide, big numbers see close.
Read more about focal length →How much smaller your sensor is than full frame — it narrows the view like a digital zoom.
Read more about crop factor →50mm × 1.5 = 75mm
What your lens looks like on a full-frame camera.
Read more about effective focal length →How much of the scene fits in frame. Longer lens or bigger crop = narrower view.
Read more about field of view →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:
(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.)
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:
Think of crop factor like a digital zoom - it makes everything appear closer without actually changing your lens.
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!
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: