4 ms·

This means that the true resolution of digital cameras is roughly one third of the advertised megapixel value, depending on the exact Bayer matrix design.

andy_ppp 4y ago
Well that’s sort of true but the algorithms that decide on which pixel has which colour are better than just the number of underlying RGB pixels…
_ph_ 4y ago
It is roughly half of the pixel count, as the Bayer interpolation gives better resolution than a naive conversion. Also, a lot of detail is in the green channel, which is registered by half of the total pixels.
SiempreViernes 4y ago
Only if you consider raw pixel count in a single channel as the only "true" measure.
verall 4y ago
The true resolution of digital cameras isn't measured in pixels, it's measured in cycles per pixel and then related to the sensor size and pixel pitch[0]. Camera sensor pixels are not squares like the pixels in a digital image, they are point samples. You can then interpolate from the point samples onto an arbitrary number of digital pixels, so what matters is basically how close you can still see edges between lines, which depends on more things than the sensor size. When megapixels are quoted for a digital camera, they are either quoting sensor size (resolution) (like on real engineering documentation) or they are just quoting the highest resolution digital image they think they can get away with the software producing (marketing, advertisements), which is arbitrary, which is part of why you do hear not to just select a camera with the most megapixels. It's a pretty deep topic and people do get degrees in basically just digital imaging. Not me though! I don't really understand most of this stuff... [0] https://www.image-engineering.de/library/technotes/742-units-and-conversions-for-resolution https://www.image-engineering.de/library/technotes/742-units...
- alok-g 4y ago
  It's only an approximation that cameras do point sampling, as the sensors are obviously not points. That camera sensors mean a different thing for a pixel than what's typical for an image or an electronic display is a matter of convention. True that interpolation is possible, but that's no reason to use different conventions as noted above. I have seen a display manufacturer manipulate the same to artificially boost their resolution specifications.

andy_ppp 4y ago

Well that’s sort of true but the algorithms that decide on which pixel has which colour are better than just the number of underlying RGB pixels…

_ph_ 4y ago

It is roughly half of the pixel count, as the Bayer interpolation gives better resolution than a naive conversion. Also, a lot of detail is in the green channel, which is registered by half of the total pixels.

SiempreViernes 4y ago

Only if you consider raw pixel count in a single channel as the only "true" measure.

verall 4y ago

The true resolution of digital cameras isn't measured in pixels, it's measured in cycles per pixel and then related to the sensor size and pixel pitch[0]. Camera sensor pixels are not squares like the pixels in a digital image, they are point samples. You can then interpolate from the point samples onto an arbitrary number of digital pixels, so what matters is basically how close you can still see edges between lines, which depends on more things than the sensor size. When megapixels are quoted for a digital camera, they are either quoting sensor size (resolution) (like on real engineering documentation) or they are just quoting the highest resolution digital image they think they can get away with the software producing (marketing, advertisements), which is arbitrary, which is part of why you do hear not to just select a camera with the most megapixels. It's a pretty deep topic and people do get degrees in basically just digital imaging. Not me though! I don't really understand most of this stuff... [0] https://www.image-engineering.de/library/technotes/742-units-and-conversions-for-resolution https://www.image-engineering.de/library/technotes/742-units...

alok-g 4y ago
It's only an approximation that cameras do point sampling, as the sensors are obviously not points. That camera sensors mean a different thing for a pixel than what's typical for an image or an electronic display is a matter of convention. True that interpolation is possible, but that's no reason to use different conventions as noted above. I have seen a display manufacturer manipulate the same to artificially boost their resolution specifications.