Pixel Pitch
The centre-to-centre distance between adjacent photosites on a sensor.
Formula / rule
Pitch = sensor width / horizontal pixels
Measured in
µm
In depth
Pitch determines how much light each photosite can gather and therefore its individual noise behaviour, but it does not determine overall image quality — a sensor with smaller, noisier pixels can match one with larger pixels once the images are viewed at the same size. Pitch also sets the aperture at which diffraction becomes visible.
Examples in practice
A 61-megapixel full-frame sensor has a pitch near 3.8 µm; a 12-megapixel one of the same size is close to 8.4 µm.