Quote Originally Posted by Daniel Browning


The briefest summary of my position is Noise scales with spatial frequency. A slightly longer model describing what I think happens with pixel size follows:
  • "The amount of light falling on a sensor does not change, no matter the size of the pixel. Large and small pixels alike record that light falling in certain positions. Both reproduce the same total amount of light when displayed."



I am in no way capable of mathematically proving you wrong. It's just not my background, unfortunately. However, I can't seem to accept your theory as true. If 100 billion photons of light are landing upon the sensor from an evenly-white-illuminated image, those photons will land upon 10 million pixels with 10,000 photons per pixel. If they land upon a same-size sensor of 15 million pixels, there are only 6,666 photons per pixel. That may be enough pixels for an accurate reading, but if the light gets darker there will be so few photons hitting each pixel that it's down to extremely significant steps, and that's where noise crops in.