What is pixel binning? Why a 200 MP camera saves 12 MP photos

How does pixel binning work?

Tiny pixels collect little light, which means grainy pictures indoors and at night. Binning sensors use a colour filter where groups of 2x2 or 4x4 pixels share one colour. In normal mode the camera adds each group together and reads it as a single pixel, as if the sensor had fewer, bigger pixels.

The pattern has brand names. Samsung calls it Tetrapixel or Tetra²pixel, Sony and others use the term Quad Bayer, and the idea is the same: groups of same-colour pixels that can be read one by one or as a block.

Many phones also use the full sensor for zoom. Cropping the centre of a 50 MP sensor gives a 12 MP image at 2x with no digital upscaling, which is why some cameras market a lossless 2x mode.

What does binning mean for your storage?

Binned shots are smaller files. A 12 MP JPEG is a few megabytes; the same scene in 200 MP mode can be ten times that. People who switch to the high-resolution mode for one landscape and forget to switch back fill their phones fast. Check the resolution label in the camera's top bar.

• Use full resolution for bright scenes you may crop or print.
• Use the default binned mode for people, indoors and night shots.
• Look for large files with a file manager sorted by size.

Video works the same way. A 200 MP sensor records 8K video by combining four pixels into one, so even high-end video does not use every pixel.

Is a binned photo lower quality?

Not in most real conditions. In dim light the binned image is cleaner, and the phone's processing is tuned for it. Full-resolution files show more detail only in good light and when you zoom in. The megapixel page explains why the number on the box says little about image quality.

For a cleaner deciding which shot to keep, sharpness and exposure matter more than resolution; see how an AI cleaner decides.

Detail in a full-resolution shot also depends on the lens. Small phone lenses often cannot resolve 200 million separate points, so the extra pixels record blur and noise as much as detail.