... 5.6.1 Full Well Depth . ... 5.6.4 Shutter Stability . 5.6.5 Fringing . ... Conceptually, full well depths can be derived by analyzing images of a rich starfield taken at two significantly different exposure times, identifying bright but still unsaturated stars in the short exposure image, calculating which stars will saturate in the longer exposure and then simply recording the peak value reached for each star in electrons (using a gain that samples the full well depth, of course). ...