[Solved] Final stack with calibration frames is completely dark

binning is all 1x1

Posted by: @ancalime

Hi. I recently have shot the Rosette Nebula. Now when I want to integrate it produces a myriad of different errors, so I decided to do some troubleshooting for myself. When I stack the lights and calibrationframes in APP, I get a dark picture. When I do the same with WBPP in Pixinsight, I get a very psychedelic pink picture with red and green horizontal lines. When I try to stack in DSS, and tell DSS to use 100% of the frames, it subsequently throws out 50% of the frames, and produces a similar picture as the PI one, only this time it's black with the horizontal lines. Now, when I only stack the lights in APP... I get a proper picture.... but, of course, uncalibrated, so have lots of amp glow, noise, etc... As soon as I add the dark frames in APP (not even the flats or darkflats/flatdarks (whatever your fancy)) I get a complete and utter black picture. As black as ink. So, I concluded that it must be the dark frames that are the culprit here. However, the light frames are shot at gain 120, 60s shots, -10C temperature and with the ASI 183mc pro. So are the darks. Everything is the same. I updated to version 1.083 and when I try to apply the darks with the lights I get the below error. I also tried to play a bit with the star detection

Now, my data is not underexposed, and I do not have a light leakage in my OTA, however, I can't make heads or tails on the 2nd one

What is a different sensor offset/pedestal? If I were to take new calibration frames, would that fix the problem?

I must mention that I updated my capturing software Nina recently to the most updated version. The calibration frames were taken with an older version of Nina.

Equipment used

Redcat 51

Skyguider Pro

Zwo ASI183MC pro

Optolong L-Extreme filter

Capturing software: Nina 2.0

 

All light frames were checked for artifacts, double stars, movements etc.

 

P.S. @Mabula, very good work on the speed improvement

 

 

Hi Gideon @ancalime,

You are receiving a legitimate warning on your data and definitely not an error 😉

No application, like you state, seems to be able to make a good result with your calibration data so that definitely indicates a severe data problem like APP is warning you.

Since you are sure that you don't underexpose and don't have a light leak, your issue must be that your calibration data has a different sensor offset when compared to the offset of your lights.

Depending on the capture software, you can set both the sensor offset and sensor gain when you start your exposure session.

Since you have shot the calibration data with an older Nina version, it is very likely that the old calibration data has a different sensor offset than the lights that were shot with the newer Nina version.

As a rule to prevent problems, don't use different software for shooting your lights and calibration data and also don't use different versions of the same software to prevent the same problems.

Best solution will be to shoot new calibration data with the same Nina version and then all should be okay 😉 if you shoot with the same sensor offset and gain.

Mabula

To the process of deduction I have more or less come to that same conclusion Mabula and will give that a try tomorrow. I have had a look and those darks indeed look a bit on the stale side. Will redo and let you know here if I was succesful

New darks did the trick. Thanks for the tip

Posted by: @ancalime

New darks did the trick. Thanks for the tip

Excellent @ancalime, so it means that the new Nina version works rather differently than the old one in terms of camera control 😉 That is why you want to be careful with different versions even of the same software when it comes to data calibration.

Glad it is solved 😉