See what a camera sensor sees

1. Light, not color

   A sensor is a grid of millions of light-sensitive elements. Each one measures how much light falls on it, but not its color.

2. A filter on every element

   To get color, each element sits under a tiny filter that passes only red, green or blue. So the raw image is a mosaic of single-color dots.

3. Demosaicing

   The camera fills in the two missing colors of every pixel from its neighbors. It’s a good guess, but not a perfect one: look for color fringes on fine edges and moiré on fine patterns.

• Bayer (RGGB)

  The most popular filter, used in iPhone cameras. Named after its inventor, Bryce Bayer.

• Quad Bayer

  An enlarged Bayer, each color patch split into 4 elements. Used in the 48MP main camera of iPhone 14 Pro and later.

• X-Trans

  Fujifilm’s filter: more green and a less regular layout, designed to resist color moiré.

• CYGM

  Cyan, yellow, green and magenta, for more accurate brightness. Used in early Nikon and Canon cameras.

• CYYM

  Cyan, yellow, yellow and magenta. Used in a few Kodak DSLRs.

• RGBE

  Sony’s red, green, blue and emerald, from some of its early digital cameras.

• RGBW Pro

  Red, green, blue and white. The clear element passes light of any color, for higher sensitivity.

• RYYB Pro

  Red, yellow, yellow and blue, for more light in the dark. Used in the Huawei P30 series.

• RGB

  The full-color picture with no filter losses, for comparison.

A camera, too

• Take photos with the filter applied. They’re saved to a “RAW Experience” album in Photos.
• Use the back or the front camera.
• Flash: the torch for the back camera, a white screen for selfies.
• Long exposure of 1, 3 or 10 seconds, or hold the shutter for as long as you like.
• Shoot with the volume buttons, or with the Camera Control on iPhone 16 and later, which also picks the pattern and the pixel size.
• An introduction to how image sensors work, and a note on every pattern.