The CCDs and their associated signal chains have readout noise levels (in the absence of signal shot noise or interference) of approximately 5e - . The analog-to-digital converter is highly accurate, and makes virtually no contribution to the read noise, other than the normal information loss caused by digitization of the signal. ... Note that all calculations of sensitivity in this manual assume gains of 7 and 14 for two gain channels, choices very close to the measured gains. ... 0.41 . ...