Poor integration results with 2.0.0-beta19 (Linux)

Did you try the option: cosmic ray / noise reducer in the analyse stars tab? This is likely what will fix this as we had some changes here that make most data registration more robust, but without calibration files you likely need this option.

Hi Vincent,

I do not want to mess up my working 1.083.2 version - so I have installed an additional 2.0.0-beta19 inside a Windows VM for testing purpose.

I get the same blurry result and it makes no difference whether the "cosmic ray / noise reducer" in the "analyse stars"-tab is checked or not.

So - I can clearly say, that it is not a Linux problem as for the Windows-Version the problem is the same!

Regards, Jochen

I have also tried to reduce the #stars target to 60 - still, the result is the same...

Ok, that is interesting, I wonder if APP is registering on the hot pixels, which is why that reducer is there. If that still doesn't work it may very well be due to the lack of dark frames. Are you able to upload your dataset for me to try?

Hi Vincent!

Thank you for your effort! I have now uploaded the two sessions into different folders which I had combined to one stack.

Regards, Jochen

PS: no hurry - 1.083.2 works fine for me for the moment!

Looking at the result now, are you able to go for more than 10s per sub? I think that will be beneficial to increase the signal to noise ratio. The noise is definitely the problem. I integrated each session separately.

Session 1 settings:

- Tab 2; hot pixel kappa to 2.0

- Tab 3; cosmic reducer set to 10

Session 2 settings:

- Tab 2; hot pixel kappa to 2.0

- Tab 3; cosmic reducer to 17

Due to the high noise this has to be set quite high and we changed this as it is more robust for other tricky datasets.

The result of session 2, I think session 1 isn't contributing much due to lack of signal (right click the image to open it in a new tab):

I played a bit with the stretch, calibrated as much light pollution as possible and cropped off the difficult parts, color corrected the stars, upped saturation and added contrast. Is the stellina able to dither? The noise that looks like diagonal stripes is walking noise, which can be removed by dithering during the data collection.

Hi Vincent,

Thank you - but hmm... I am not yet convinced with the result. The Stellina-Roboscope is basically an APO on an Alt/AZ mount with a field rotator. Therefore, unfortunately settings are very limited. For example, there is no way to create flats (due to the field rotator), there is no way to dither and the maximum exposure time is 20s. The M20 was taken from Stellinas pre-defined catalogue of targets and the preset exposure for this object is 10s.

Still, with the 1.083.2 I can archive reasonably good results without having to set hot pixel kappa or cosmic reducer.

For example - this is the result of 4 sessions (it includes the 2 sessions I have uploaded). It has been stacked with 1.083.2 with the settings mentioned in post #1 and it is post-processed with PI and PS. Exposure is 612x10s = 1,7 hrs

So - IMHO something severe must have changed between the versions of APP - but what?

Regards, Jochen

Sorry, missed your reply! So, I only used 2 sessions and did not external processing, the issue I'm seeing is walking noise for sure. With more data, and postprocessing you can stretch that into the background (which is why you have a darker backround). Do you have a screenshot without postprocessing from APP between 1.083 and 2.0?

Hi Vincent - don't worry - as I said it is not an urgent matter as 1.083 is working fine.

I did some more testing and I have attached some stacking-results without any post-processing (except auto-stretch in PI and turn/flip the picture).

This is the (raw) picture as it comes out of 1.083 (91% Integration (=161x10s) | integrate=average, weights=quality | adaptive rejection on with kappa high=2.8 | LNC 2nd deg./ 3 iterations):

1.083 stack:

Then, I have tried the same in 2.0.0-beta with the same settings as in 1.083 - still without setting the hot-pixel kappa and cosmic reducer. This does the "bad result":

2.0.0-beta19 stack without hot-pixel kappa and cosmic reducer:

Then, I did the same in 2.0.0-beta with the additional settings you have recommended AND I have stacked both sessions separately with the hot pixel kappa settings you had recommended:

Session1: hot pixel kappa=2.0 | cosmic reducer=10  Session 2: hot pixel kappa=2.0 | cosmic reducer=17

I have then combined the stacks of Session 1 and 2 into one and I must say, that the result seems to be even a little better than the 1.083 result. The background has less walking noise and seems to bee a little smoother and cleaner.

2.0.0-beta19 stack with hot-pixel kappa and reducer:

I will try to play with my settings. Apart from Stellina... with my other telescopes, I do not have these kind of problems as I can use calibration-frames and dithering.

Thank you so far!

Regards, Jochen