Integration of Canon wide angle shot fails with different exposures

[gottsch]

Hello,

As per forum search the ImageIntegration should be robust against exposure time variations. This fails for my Canon raw wide angle images.  I have 10 images (CR2) with Canon kit lens. Most are 30sec. But 2 are different. 20sec and 19sec. When I run ImageIntegration it fails saying:
*** Error: D:/Images/Digital_Camera/Reisen/2019_NZ_Sibylle_Donna/Astroaufnahmen/PI_Serie2/registered/IMG_0569_c_r.xisf: Zero or insignificant signal detected (empty image?)
<* failed *>
How do I fix it?

Thanks,
Gert

[pfile]

the calibration could be bad for those images - if you open that image and hit the STF does it look normal, or black with just some saturated stars?

rob

[gottsch]

Hello

@pfile: There seems to be some color bug in calibration. See the below screen copy.
Left column is the Canon raw (CR2) 30sec, 20sec, 30sec.
Right column same images after calibration.
The 20sec has bad calibration. What is the bug?



Clear Skies,
Gert

[pfile]

there's no attachment visible...

how were these calibrated? bias? darks? do the dark durations match the light durations?

rob

[gottsch]

@pfile: Calibration is only with 30sec darks. No flat. No bias. There is a mismatch between 20sec exposure and 30sec dark. I expect the algorithm to compensate. I'll probably go ahead an process without darks. That should work without bug.

Clear Skies,
Gert

[pfile]

you can't scale a dark without a bias frame... that's probably your problem.

what i'd do to start is just take some 1/8000 exposures (or the fastest shutter speed you can get on your camera) and make a master bias from them and just use that rather than a dark. the amount of dark signal in a 20sec exposure is probably pretty low anyway, even though (i assume) you are working with an uncooled DSLR.

rob