In microscopy we often can sacrifice spatial resolution to collect more photons per pixel. Using sCMOS sensor and binning by factor of 2, we can get bump (up to 4x) in our signal-to-noise ratio (SNR). There is a bit of difference between CCD and CMOS here, but since all novel DSLRs I know use CMOS, it doesn't matter.
Now question. Does taking underexposed picture (say, 1 stop: 1/60s instead of recommended 1/30s) with modern DSLR and binning (downsampling) image afterwards will give same result in terms of image quality as at recommended exposure?
What about shooting at ISO 1600 and downsampling, how close result will come to image taken with ISO 800 and 2x longer exposure?
Is it realized in this way or similar in any practical cameras as a function?
PS: 1) I will experiment myself as soon as get hands on my fancy new dslr 2) googling referred me only to some shady forums without much useful discussions 3) I know that if you underexpose, you sacrifice dynamic range, essentially putting all those intensities into lower part of histogram, which effectively results in 6-8 bit images instead of 12 or 14.