Glossary
Pixel binning
A sensor mode that combines 2×2 (quad bayer) or 3×3 (nona-binning) adjacent pixels into one virtual pixel, trading resolution for low-light sensitivity. The reason 200 MP phone sensors usually output 12.5 MP photos.
A 200 MP sensor with 0.6 µm pixels bins 4×4 down to 12.5 MP at effective 2.4 µm — capturing 16× the light per output pixel. The full 200 MP resolution is available in good light if you ask for it.
Why it works
Photographic noise is proportional to the square root of light captured. Combining pixels increases captured light without proportionally increasing noise — gross SNR improvement.
Tradeoffs
- Detail. Binned output has lower true resolution than the marketing figure suggests.
- Honesty. A 200 MP sensor outputting 12.5 MP is competing with 12 MP sensors that have 2.4 µm native pixels. The dedicated-pixel camera often has cleaner output because there's no Bayer interpolation cost.
The headline megapixel number for binning-first sensors should be read as "what they could do" rather than "what they do."
Where this matters
Categories that use pixel binning
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