Several tricks used for low level surveillance cameras:   
   1) Remove the IR blocking filter. This extends its sensitive range to nearly   
   double the wavelengths. The near IR used is often several times more intense   
   than the visible light, giving a surprising increase in illumination. The   
   tradeoff is loss of color    
   so the output is converted to monochrome.   
   2) Slower sample rate - instead of 30 Hz, the camera can slow to (say) 4 Hz,   
   giving another huge boost in sensitivity.   
   3) Fast optics - f/1.6 lenses are common which are faster than the human eye.   
   4) High photon efficiency - backside illuminated microlens equipped sensors   
   can capture and detect more of the photons (light) than the eye does.   
   5) (cheating?) Use of IR illumination. A tiny amount of electrical power can   
   light a surprisingly large area due to the efficiency of IR LEDs.   
      
   All this has been available and built into products for years now...   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)