5 ms·

Since the "pixels" are either formed at every intersection of 4 photosites (overlapping each other) or by interpolating data for each color to include the "miss

Since the "pixels" are either formed at every intersection of 4 photosites (overlapping each other) or by interpolating data for each color to include the "missing" photosites (which is effectively the same), the megapixel count should fairly accurately represent both the number of photosites and the number of pixels in the output image. I'm not exactly sure how the edge pixels are treated, but the difference in number between pixels and photosites should be on the order of a few thousand at most.

deleted 5y ago
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barbazoo 5y ago
Are you saying that one photosite might be included in more than one pixel and therefore the overall pixel count is roughly equal to the number of photosites?
- falcrist 5y ago
  I'm saying that each photosite definitely is included in more than one output pixel, and I'm also saying that the number of output pixels should be about the same as the number of photosites. This is obviously capturing less information than if you had a completely separate set of photosites for each pixel, but the megapixel count of cameras is nevertheless accurate. Modern cameras sometimes come with a "pixel shift" function, which uses the image stabilization system to take 4 images each shifted one photosite from the others to construct an image where each pixel contains the information of 4 independent photosites with no sharing between the pixels. The resolution of the final image is the same as a normal image, but the result is much clearer, and far less likely to suffer from blue/red moire.
ansible 5y ago
> I'm not exactly sure how the edge pixels are treated ... It is quite common to have more than the "nominal" number of pixels in a sensor array. So there are extra pixels for the edges.
- falcrist 5y ago
  Ah yes. I had forgotten about this. I believe there are also extra pixels at the edge of some sensors that are unexposed, and just used for calibration purposes.

deleted 5y ago

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barbazoo 5y ago

Are you saying that one photosite might be included in more than one pixel and therefore the overall pixel count is roughly equal to the number of photosites?

falcrist 5y ago
I'm saying that each photosite definitely is included in more than one output pixel, and I'm also saying that the number of output pixels should be about the same as the number of photosites. This is obviously capturing less information than if you had a completely separate set of photosites for each pixel, but the megapixel count of cameras is nevertheless accurate. Modern cameras sometimes come with a "pixel shift" function, which uses the image stabilization system to take 4 images each shifted one photosite from the others to construct an image where each pixel contains the information of 4 independent photosites with no sharing between the pixels. The resolution of the final image is the same as a normal image, but the result is much clearer, and far less likely to suffer from blue/red moire.

ansible 5y ago

> I'm not exactly sure how the edge pixels are treated ... It is quite common to have more than the "nominal" number of pixels in a sensor array. So there are extra pixels for the edges.

falcrist 5y ago
Ah yes. I had forgotten about this. I believe there are also extra pixels at the edge of some sensors that are unexposed, and just used for calibration purposes.