**This is a more detailed description of [[/glossary/#Pixel Binning]], including specific examples from Canon cameras.**

When the cameras software does not process every single [[/glossary/#photosite]], what happens is that every single [[/glossary/#Bayer]] photosite processed by the camera might be obtained by averaging data from a few photosites. This averaging process happens in the [[/glossary/#analog]] domain. When pixel binning is used, the image received/processed by the camera software is already pixel-binned (the image sensor is not read out at its full resolution).

Advantages:
  * relatively simple to implement with analog electronics;
  * all sensor photosites contribute to the final image (nothing is lost), unless [[/glossary/#Line Skipping]] is used;
  * lower data rate to process for a single LiveView or video frame;
  * easier to achieve a high frame rate without requiring huge processing power (compared to a complete readout at full resolution, followed by a resizing step in digital domain);
  * reasonably good performance on high-frequency details (very few aliasing/moire issues on a [[/glossary/#Resolution Chart]]).

Disadvantages:
  * less image detail (compared to a full resolution image resized to match video resolution);
  * some noise introduced by analog electronics (compared to averaging the same pixels in software, from a full resolution image);
  * available binning factors are [[/glossary/#hardwired]].

Most Canon cameras use [[/glossary/#Line Skipping]] (a variation of pixel binning, which only combines the photosites from one single line, and discards the data from the other lines in a 3x3 or 5x3 block, see below). It's easier to implement in hardware, but the main disadvantage of line skipping is poor performance with high-frequency details (severe [[/glossary/#aliasing]]/moire issues).

**Canon cameras generally use the following pixel binning modes:**

Pure pixel binning modes (without line skipping) - 5D Mark III:

{{ https://a1ex.magiclantern.fm/bleeding-edge/lv-binning/5d3-lv-binning-cell-v2.png?100|}}
  * 3x3 binning: for every pixel, 9 photosites (3 lines x 3 columns) of the same [[/glossary/#Bayer]] color are averaged together. Used on 5D Mark III in 1080p video modes. See figure ->
  * 5x3 binning: for every pixel, 15 photosites (5 lines x 3 columns) of the same [[/glossary/#Bayer]] color are averaged together. Used on 5D Mark III in 720p video modes.
  * 1:1 crop (no binning, sometimes called "crop mode"). Used on all cameras when capturing a full resolution image. Also used on Canon cameras in x5/x10 zoom modes in LiveView.

Pixel binning modes with line skipping - most Canon EOS cameras:

{{ https://a1ex.magiclantern.fm/bleeding-edge/lv-binning/5d2-lv-binning-cell.png?100|}}
  * 3x3 column binning / line skipping. For each 3x3 block of photosites, only one of the 3 lines is averaged (all 3 columns from this line, of the same Bayer color, being averaged together), in order to create a pixel in the LiveView image. The remaining 2 lines are discarded (skipped); that is, the video image is created from 33% of the photosites on the image sensor. Most Canon EOS cameras use this method to implement 1080p video (5D Mark III is an exception). See figure ->
  * 5x3 column binning / line skipping. Used by most Canon EOS cameras to implement 720p video. For every line read out from the sensor, 4 lines are discarded (skipped).

Pixel binning patterns will affect camera's [[/glossary/#native resolution]] in video mode.

Custom binning modes enabled by Magic Lantern (currently available in some experimental versions of the [[/glossary/#crop_rec]] module):

  * 1x3 binning: a custom binning technique which operates on blocks of 1 line and 3 columns. It acts as a middle ground between 3x3 (1080p) and 1:1 (full resolution). This mode uses all photosites from the image sensor, by reading every single line, and does not have any noticeable aliasing/moire issues. Also known as [[/glossary/#Anamorphic]].
  * 3x1 binning / line skipping: another custom binning technique, using blocks of 3 lines and 1 column, requiring the same data rate as with 1x3 binning. Not very useful in practice, because of the aliasing/moire issues.
  * 3x3 line/column skipping: from each 3x3 group of photosites, only one photosite is read out; all others are discarded. The layout is a little unusual. [[https://a1ex.magiclantern.fm/bleeding-edge/lv-binning/extreme-moire.html|Extreme aliasing/moiré issues]].  See figure > {{ https://a1ex.magiclantern.fm/bleeding-edge/lv-binning/binmode-3x3-rcskip-extrememoire.png?100|}}


FIXME: way too long (move to new page?) (agreed)\\

-> [[ml>forum/index.php?topic=16516.0|ML Forum: Pixel binning patterns in LiveView]]\\
-> [[https://a1ex.magiclantern.fm/bleeding-edge/lv-binning/binning-modes.html|Simulation: 1x3 "column binning" vs 3x1 "line skipping" vs 3x3 binning/skipping]]\\
-> [[/glossary/#Line Skipping]]\\
-> [[/glossary/#Native Resolution]]\\
-> [[/glossary/#crop_rec]]\\
-> [[/glossary/#Anamorphic]]\\