Understanding Dark Noise and Shot Noise
Posted: Sat May 18, 2019 8:56 am
Hello Robin,
with high interest I watched the video of your recent speech at PAS (https://www.youtube.com/watch?v=3RH93UvP358) and read your tutorial on "Picking the correct exposure for Deep Sky" here in the forum (viewtopic.php?f=35&t=456).
There is one thing though that I do not understand, maybe you can help me along.
The physics of dark noise, read noise and shot noise is clear. I do not understand though why you only consider shot noise coming from the photons of the image, shouldn't there also be shot noise introduced by the dark noise (aka thermal noise)? I would assume that the thermal noise also follows a poisson distribution, i.e. the same math should apply, shouldn't it?
Or can one neglect this considering that the dark current is much lower than the signal coming from light pollution?
Thanks for your advice in advance,
Stefan
with high interest I watched the video of your recent speech at PAS (https://www.youtube.com/watch?v=3RH93UvP358) and read your tutorial on "Picking the correct exposure for Deep Sky" here in the forum (viewtopic.php?f=35&t=456).
There is one thing though that I do not understand, maybe you can help me along.
The physics of dark noise, read noise and shot noise is clear. I do not understand though why you only consider shot noise coming from the photons of the image, shouldn't there also be shot noise introduced by the dark noise (aka thermal noise)? I would assume that the thermal noise also follows a poisson distribution, i.e. the same math should apply, shouldn't it?
Or can one neglect this considering that the dark current is much lower than the signal coming from light pollution?
Thanks for your advice in advance,
Stefan