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No, the Canon sensors also have only one photosite per pixel -- they're still using a Bayer filter on a monochromatic sensor.

jonah 16y ago
Ok, here we're getting into confusion about terminology here. To clarify: In the Bayer filtered Canon CCD each individual photosensor is covered in a colored filter [1] in a pattern such as: B G G R So when capturing an image 1/4 of the sensors are capturing blue light, 1/4 capturing red, and 2/4 capturing green. In contrast the CCD in the rover's cameras do not have filters in front of individual photosensors. Instead, there is a set of filters on a disc which are mechanically positioned in front of the sensor. Using this method three images are taken. On each with a red, green, and blue filter covering 4/4 of those same sensor elements giving you 2x-4x the number of elements capturing each color and thus much higher image quality at a given resolution. B B B B then G G G G then R R R R Similar multi-shot technology was used in the early days of terrestrial digital photography to provide better color, exposure latitude and resolution. [2] for a bit of discussion on multishot vs. single shot medium format digital camera backs. [1] http://en.wikipedia.org/wiki/Bayer_filter http://en.wikipedia.org/wiki/Bayer_filter [2] http://www.luminous-landscape.com/reviews/cameras/h3d50ii.shtml http://www.luminous-landscape.com/reviews/cameras/h3d50ii.sh...
- Tamerlin 16y ago
  The part that threw me off was where you said that the Canon sensor contains 3 photosites per pixel -- which based on this pots leads me to believe that you meant that it uses 3 photo sites to record each pixel, which is still not entirely accurate; the Rover's capture every color at every photosite, so they use all of their sensor's resolution. Canon (and everyone else but Foveon, for that matter) making a single-shot sensor can't do that, they instead sacrifice the real resolution of the sensor due to the Bayer filter, and use interpolation to make up the difference.

jonah 16y ago

Ok, here we're getting into confusion about terminology here. To clarify: In the Bayer filtered Canon CCD each individual photosensor is covered in a colored filter [1] in a pattern such as: B G G R So when capturing an image 1/4 of the sensors are capturing blue light, 1/4 capturing red, and 2/4 capturing green. In contrast the CCD in the rover's cameras do not have filters in front of individual photosensors. Instead, there is a set of filters on a disc which are mechanically positioned in front of the sensor. Using this method three images are taken. On each with a red, green, and blue filter covering 4/4 of those same sensor elements giving you 2x-4x the number of elements capturing each color and thus much higher image quality at a given resolution. B B B B then G G G G then R R R R Similar multi-shot technology was used in the early days of terrestrial digital photography to provide better color, exposure latitude and resolution. [2] for a bit of discussion on multishot vs. single shot medium format digital camera backs. [1] http://en.wikipedia.org/wiki/Bayer_filter http://en.wikipedia.org/wiki/Bayer_filter [2] http://www.luminous-landscape.com/reviews/cameras/h3d50ii.shtml http://www.luminous-landscape.com/reviews/cameras/h3d50ii.sh...

Tamerlin 16y ago
The part that threw me off was where you said that the Canon sensor contains 3 photosites per pixel -- which based on this pots leads me to believe that you meant that it uses 3 photo sites to record each pixel, which is still not entirely accurate; the Rover's capture every color at every photosite, so they use all of their sensor's resolution. Canon (and everyone else but Foveon, for that matter) making a single-shot sensor can't do that, they instead sacrifice the real resolution of the sensor due to the Bayer filter, and use interpolation to make up the difference.