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Kudos to your dad! Every time I explain how a digital camera works to people, invariably it's the concept and application of the Bayer filter that causes their

Kudos to your dad! Every time I explain how a digital camera works to people, invariably it's the concept and application of the Bayer filter that causes their jaw to drop. Most people think 50 megapixels = 50 red, 50 blue, and 50 green megapixels, so it's quite eye-opening. That our eyes work similarly with cones tuned to specific frequencies is just icing on the cake after that.

ISL 4y ago
For a Foveon, the way you first think it works is the way it works :). https://en.wikipedia.org/wiki/Foveon_X3_sensor https://en.wikipedia.org/wiki/Foveon_X3_sensor
dylan604 4y ago
Yeah, realizing the actual image is only about 1/4 of the resolution of the sensor is something not everyone grasps. Marketing of course doesn't try to explain it either. I tend to take it too far by then explaining the benefits of using 3-chip monocolor sensors (or if not real-time, a single sensor triple flashed) to get the full resolution for each color channel. These are usually CCDs instead of CMOS, but the theory is the same. This is how most astronomy things work, like the Hubble, but instead of RGB, they use other filters that get "colorized" into RGB-ish.
- ulfw 4y ago
  It's really not 1/4 of the resolution. That's the beauty of the demosaicing process.
  - dylan604 4y ago
    sure, and i knew the pedantics would beat me up over it (maybe rightly so, but i tried to use a number hyperbolically to make it obvious). however, it's not the full resolution of the chip. hence the use of monochrome chips for "full" resolution.
    - Gare 4y ago
      Luma is at full resolution, chroma is "upscaled", but we're less sensitive to color than to light so it's almost as good. Most JPEG uses subsampling on chroma channels anyway.
    - jimmydorry 4y ago
      Pedants, actually. :) I couldn't help myself not to point out that the people being pedantic are pedants. Thanks for the example though, as it was a simple way of mostly expressing a complicated concept.
      - dylan604 4y ago
        i'm going to go with autotypo. yeah, that's it.
    - ulfw 4y ago
      It's not about being pedantic, but that's literally the whole point of the Bayer process (which is what was being discussed). If we were fine with getting 1/4 resolution output we'd just put one color filter for each sensor pixel and don't Bayer demosaic anything and call it a day.
- jack1243star 4y ago
  > Marketing of course doesn't try to explain it either. I remember early CCD digital camera brochures stating "actual resolution", and "enhanced resolution" (or something similar), where the latter is ~3x the former number. I wonder if this was referring to the demosaicing procedure.
  - bayindirh 4y ago
    Nope, since the early sensors were very low resolution, many cameras included interpolation engines inside, and some of them were pretty good at what they did. They used blurry language to thinly veil the fact that the 1024x768 image you got indeed started its life as 640x480 one out of the sensor.

ISL 4y ago

For a Foveon, the way you first think it works is the way it works :). https://en.wikipedia.org/wiki/Foveon_X3_sensor https://en.wikipedia.org/wiki/Foveon_X3_sensor

dylan604 4y ago

Yeah, realizing the actual image is only about 1/4 of the resolution of the sensor is something not everyone grasps. Marketing of course doesn't try to explain it either. I tend to take it too far by then explaining the benefits of using 3-chip monocolor sensors (or if not real-time, a single sensor triple flashed) to get the full resolution for each color channel. These are usually CCDs instead of CMOS, but the theory is the same. This is how most astronomy things work, like the Hubble, but instead of RGB, they use other filters that get "colorized" into RGB-ish.

ulfw 4y ago
It's really not 1/4 of the resolution. That's the beauty of the demosaicing process.
- dylan604 4y ago
  sure, and i knew the pedantics would beat me up over it (maybe rightly so, but i tried to use a number hyperbolically to make it obvious). however, it's not the full resolution of the chip. hence the use of monochrome chips for "full" resolution.
  - Gare 4y ago
    Luma is at full resolution, chroma is "upscaled", but we're less sensitive to color than to light so it's almost as good. Most JPEG uses subsampling on chroma channels anyway.
  - jimmydorry 4y ago
    Pedants, actually. :) I couldn't help myself not to point out that the people being pedantic are pedants. Thanks for the example though, as it was a simple way of mostly expressing a complicated concept.
    - dylan604 4y ago
      i'm going to go with autotypo. yeah, that's it.
  - ulfw 4y ago
    It's not about being pedantic, but that's literally the whole point of the Bayer process (which is what was being discussed). If we were fine with getting 1/4 resolution output we'd just put one color filter for each sensor pixel and don't Bayer demosaic anything and call it a day.
jack1243star 4y ago
> Marketing of course doesn't try to explain it either. I remember early CCD digital camera brochures stating "actual resolution", and "enhanced resolution" (or something similar), where the latter is ~3x the former number. I wonder if this was referring to the demosaicing procedure.
- bayindirh 4y ago
  Nope, since the early sensors were very low resolution, many cameras included interpolation engines inside, and some of them were pretty good at what they did. They used blurry language to thinly veil the fact that the 1024x768 image you got indeed started its life as 640x480 one out of the sensor.