>>3833180>Photon shot noise dominates high ISO and is a natural consequence of the quantized nature of light.Do you have any quantitative data on that?
I honestly don't know but find it hard to believe photon shot noise would dominate anything in photographic applications.
There are so many more noise sources when using a sensor and electronics to capture images:
In no particular order:
1. fixed pattern noise due to manufacturing defects on the photosites, circuitry, microlenses, and you can include hot pixel noise here too due to defects in circuitry leaking current to nearby photosites
2. read noise when you actually read off the sensor
3. dark current noise, due to thermals *and* the probabilistic nature of electrons, which is *further* exacerbated by electron shot noise cause electrons have quantum nature too
And of those, dark current noise increases exponentially with temperature.
While photon shot noise increases with the square root of the signal decrease.
Photon shot noise exists, but unless you're trying to capture a number of photons you can count in your hands and with a sub-zero cooled camera, for which you first did dark frame subtraction etc., I doubt it dominates anything.
Also the fact that it is constant, irrelevant of technology/circuitry/manufacturing tolerances/temperature etc., and is in the very nature of light, I don't see much relevance of mentioning when comparing different optical systems, unless some of those systems approach such microscopic photosite sizes to be capturing photons in the dozens and not hundreds of dozens.
Again I don't know for sure and haven't run any numbers precisely, but from a guesstimation it seems very improbable to be of relevance for photographic applications.
It seems more of an issue in detection experiments in physics, or electron scanning microscopy etc. .
