"Gain" Setting

[wxman]

Could someone explain exactly what the "Gain" setting is on the Hikvision Cams? I realize the lower the value, the darker the image, but I'm not 100% certain as to the technical method behind this darkening. Is this identical to negative exposure value compensation (-EV)?

 

[bp2008]

My own words: Gain is like a sensitivity setting. It amplifies the signal from the CMOS sensor, making the image brighter. But it also amplifies noise such that if you max out the gain for a better image at night, it will also make the noise stronger. I can't really be any more specific than that since I am not a camera engineer. Maybe the wikipedia definition would help? https://en.wikipedia.org/wiki/Gain

The main thing to know about gain in terms of cameras is that it increases brightness (and noise) without increasing exposure time and therefore it does not add motion blur the way a longer exposure would.