>>3985665That is not a source that proves that shot noise is based off of total light, not per pixel light.
See:
https://hamamatsu.magnet.fsu.edu/articles/ccdsnr.html> the signal-to-noise ratio may be thought of as the relative signal magnitude, compared to the measurement uncertainty, on a per-pixel basis> The three primary broad components of noise in a CCD imaging system are photon noise, dark noise, and read noise, all of which must be considered in a calculation of signal-to-noise ratio.>pic rel, photons/pixel/second 