There were mentioning that binning increases SNR in CCD cameras, the source is the mirco course video “Signal to Noise Ratio” time stamp 10:15.
Hi @Grasswall, great question.
It really is as simple as more signal for the same amount of noise (thereby increasing the signa/noise ratio). Let’s say you have 4 photodiodes (pixels) each of which capture x electrons. Each of those 4 photodiodes then converts its electrons to a gray value by conversion at a (noisy) readout amplifier… let’s say it adds y noise, for an effective SNR or x/y.
In a CCD, binning results in the electrons accumulated in neighboring photodiodes to be combined before the noisy readout event, and they are all measured together in one go. So, in our example, your signal (after binning) would now be 4x, but since there is only one readout event for our binned “superpixel”, the noise remains at y, so our SNR is increased 4x.
Obviously, this comes at the cost of spatial sampling: because the merged superpixel is larger and cannot capture the same spatial information/resolution as before.
Thank you very much for your reply, this is a great explanation!
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