Signal-to-Noise Ratio (SNR)

Comparison of signal power to noise power, including dark current and other unwanted/unpredictable fluctuations. In imaging systems, it is expressed in decibel values for analog systems, and "bit" values for digital systems. Industrial cameras have no less than 46dB SNR, yielding 256 steps of contrast in the image. This corresponds to an 8 bit digital signal (2⁸ = 256). Every 6dB of an analog signal converts to 1 bit when digitized.