For a few months, I have been shooting with my QHY165C and having pretty good results using PixInsight.
Last week, I shot the Tadpole Nebula, IC410, and even though the guiding was not great, the camera worked well as far as I can tell and the newest release of PixInsight worked well.
Monday night, I shot the same IC410 but encountered some strange results that I hope you can help me understand.
I captured 45 frames using SharpCap:
- 120s Exposure
- Gain at 200 in SharpCap (roughly unity gain of 3750)
- Offset of 10 in SharpCap
I used these same settings a week ago for the same IC410, and for those frames, the processing worked as usual in PixInsight and the results were decent as far as color goes. One thing I noticed is the newest frames that do not work were captured with a minor revision to SharpCap. I double checked the settings I used and they were the same. But until I can try another capture using the old SharpCap, I cannot rule out the newer SharpCap causing an difference in how the camera operated.
The shots I took Monday night get screwed up in PixInsight after I do light frame calibration. Today, I disabled flats, darks and biases so the calibration was not using those calibration files. Yet I still get a very strange file.
If I debayer the raw, .fits file, it looks pretty normal and I can see the hint of nebula. If I put the frame from last week beside the one from this week, I can see the one from last week looks like it was exposed longer, but everything was identical. The frames I shot this week seem to have less signal, but higher SNR. And maybe the light pollution was lower and maybe the moon was different. But even if I can account for this, what PixInsight is creating with light frame calibration is totally wrong and looks corrupted. On one hand, these new frames from this week look "better". Higher SNR, less light pollution and better guiding. But, I cannot get past light frame calibration in PixInsight because they become screwed up for a reason that is beyond my knowledge.
Here is one frame from last week (what works as normal in Pixinsight) and another frame from this week, where light frame calibration creates bad results. Can someone please look at these and help me understand if my captured images are bad or if Pixinsight is creating a problem I have never run into before?
The two raw .fits files can be found here:
https://www.dropbox.com/sh/qpdfq7ivcj95y2z/AAB4x6CT1lz8O4521L8U3a3La?dl=0I have the bias, dark and flat masters but I do not think they are part of the problem. Note I did capture the flat frames using the new SharpCap and I processed those flats using the new PixInsight and that seems to work.
Could the signal in my light frames be too low? The stars look fine in "Blink".
Thank you
Bryan
