Amp Glow not correctly removed during calibration

[gvanhau]

Hello
I own a QHY8L CCD cámera in witch during the readout of the first half frame the amp canot be turned off. So there is a amp-glow in the image more or less the same as the "Canon mark".
The diference here is that the amp glow is almost constant no mater the duration of the exposure since the readout time is almost constant..
I usualy did may calibration and integration in Maxim DL, but now I am trying to do this it in PI.
What i found so far is that during the calibration of the light frames this amp-glow is not fully removed.
What shoud the correct setting be for dark calibration (and light calibration) in this case?
Should i have to turn of the dark optimization?

Regards
Geert

[zvrastil]

Hi Geert,

according to my experience with calibrating exposures from old Canon 300D, the amp glow is only removed correctly when you turn dark optimization off. Then of course, your master dark has to match both exposure and temperature (again with 300D, +/-3C temperature difference seems ok). If you have more master darks with same exposure but different temperatures, I suggest to try to calibrate one frame with all those master darks and optimization off. Then, debayer and inspect the result to see which master dark yielded best result.

regards, Zbynek

BTW - idea for wide audience - wouldn't it be possible to separate dark current from amp glow using wavelets and optimize/correct them separately? For one-shot color cameras with bayer mask, one would have to separate channels (red, green and blue pixels separately) and then combine them again, but I think it's doable. I may experiment with this approach if I find a time for it.