"The number of photons reaching individual pixels on the detector follows a Poisson distribution, with an average number of photons per pixel, N. The standard deviation is approximately √N 1."
"The number of photons reaching individual pixels on the detector follows a Poisson distribution, with an average number of photons per pixel, N. The standard deviation is approximately √N 1."
"The perceived noise in an image is then = √N / N"