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So I did some extensive tests on the QHY600C yesterday and got AIP4WIN to work also.
I chose 2 gain and 3 offset values for each readout mode and these bias/dark frames were combined with flats taken at 3 ADU values (one near saturation, one midpoint and one low). The flats however, were taken at one gain/offset value and one readout mode only.
The gain values I chose were ones that I selected as being optimum and balanced against what I would like to get out of the camera in terms of read noise v full well v dynamic range.
Findings:
Offset - made no impact whatsoever across all images. I suspect this is because a different offset value would not manifest itself here, but rather in the dynamic range of the actual image.
QHY specify that the camera is linear all the way up to 70+K in readout mode 0 and 2 with a gain of 0.
Well of course, a gain of 0 is not much cop right? And if you look at the graphs on the QHY website, a gain of 0 has a very big impact on the other camera charateristics. So bit of a pointless marketing there methinks.
Indeed, in all of the 15 sets of images I took and ran through AIP4WIN, the flats at an ADU value of 15K, resulted in lower system gain, lower readout noise and dark current. In contrast, the flats with an ADU of 50K, had the exact opposite affect.
Temp was -10degs. Darks were 5mins duration (no amp glow).
The lowest dark current recorded was 0.0006 e/pix/sec.
The highest dark current recorded was 0.011 e/pix/sec
The lowest readout noise recorded was 0.16e
The highest readout noise recorded was 1 electron
So, what I cannot explain is why the flat ADU values had such a marked affect on the results - or does it simply mean that you should take your flats using the same gain/offset values and readout modes too!?
Of particular interest to me, is that NONE of the values I recorded match or come anywhere near the values seen on the QHY website for this camera.
So obviously, what I need to do is to take that data set and run it through a different program now and compare the results.
Comments, thoughts?
Martin
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