8 bit vs 12 bit vs 16 bit

davidsliski

Hi Everyone,

I recently purchased a ZWO 174 MM cooled camera. When I plugged it in and started imaging with the camera using PHD@ guiding I was surprised to see an 8 bit read out. When I connected it to the Sky X or Maxim DL I could pick 8 bit or 16 bit readouts. This seems odd to me as the camera is 12 bits. A few questions.

1) is there a program or way to read the camera out in 12 bit mode that way I can do photometry / science with the camera

2) in 8 bit readout mode are the ADU truncated at 256 electrons or is there some type of reduction going on to allow for the full range but with less resolution (4096 vs 256 readout)

3) in 16 bit readout mode are the ADUs extrapolated to 65536 in some creative way?

Thanks,

David Sliski

Graduate Student

University of Pennsylvania

MINERVA Project

moonprince

1) is there a program or way to read the camera out in 12 bit mode that way I can do photometry / science with the camera

Yes, Sharcap3.0, Firecapture 2.6, can use 12bit ADC, and record under RAW16.

Under SKYX, MDL, you can record it at RAW16.

2) in 8 bit readout mode are the ADU truncated at 256 electrons or is there some type of reduction going

on to allow for the full range but with less resolution (4096 vs 256 readout)

8bit is only for planetary imaging, when you use high gain.

3) in 16 bit readout mode are the ADUs extrapolated to 65536 in some creative way?

Yes, each value X 16.