Curious what a recommended Flat Image AU would be?? I've heard 50% of the well depth and I understand the Well Depth of the STF 8300m is 25,000. So would that mean when taking flats I should have the average AU of 13,000?? Friends have told me I'm to take flats of around 40,000 AU. I'm very confused can you provide guidance?? Kenn
The Well Depth is measured in electrons. The camera reads out in Analog to Digital Units or ADUs. If you take that 25,000 electron well depth and divide by 0.37 e-/ADU - the camera gain - then you'll get a bigger number. The actual maximum ADU value for a 16-bit converter is 65,535. So a readout of 65,535 corresponds to 25,000 electrons. A value around 50% would therefore be around 32,767 ADUs.