DeepSkyStacker - What is up with my stack?

[Guest]

I was blessed with clear skies last night and managed four hours of 600 subs on North American Nebula with my modded Canon 600D.

No matter what settings I use for registering and stacking in DSS I get the below image. I am not sure if this is relevant but some of the images were taken after Astrophotography Tool (APT) mentioned about reaching meridian but there was a enough clearance so I did not flip. All the CR2 subs are the same orientation but perhaps that has something to do with it?

Any suggestions would be greatly appreciated.

[carastro]

Ooer!!!

What do the individual subs look like?

Any chance of a link to the Raw subs and calibration frames so we can have a "go" at stacking.   

Carole 

[Guest]

38 minutes ago, carastro said:

Ooer!!!

What do the individual subs look like?

Any chance of a link to the Raw subs and calibration frames so we can have a "go" at stacking.   

Carole 

Individual subs looked fine to me - albeit a novice me!

Yes of course I am happy to share the files - does the following link work ok for you?

https://drive.google.com/drive/folders/1DBJv1f-6_Naw5iV-jxZQpO58WB4AZNus?usp=sharing

There is a folder with the lights and another with masters for dark, flat and bias.

Really appreciate the help Carole 👌

[MarkAR]

I would try stacking the before and after meridian flip separately to see what happens.

[happy-kat]

What camera are you using and if a dslr have you turned auto rotate off

 

Edit, I see it's a 600d

Edited July 17, 2020 by happy-kat

[Guest]

Camera is Canon 600D with auto rotate definitely turned off. If you look in the folder in the link above you can just make out all subs are same orientation.

Not sure when meridian flip happened to be honest - I do wonder if APT tagged the files differently after the flip even though it was saved in the correct orientation.

Will try restacking them.

[geeklee]

13 minutes ago, Chris Wright said:

Will try restacking them.

All the previews looked fine for each sub, just varying light pollution.

You weren't stacking NEOWISE in DSS recently and there's some settings still changed from doing comets?  I threw the whole lot into APP and just said "Go" effectively.  I got a nice image out the other end (just APP's DDP stretch, no processing for LP etc):

Edited July 17, 2020 by geeklee

[TerryMcK]

I've had similar stacked images produced after integrating darks with light leaking in the filter aperture. But nothing as severe as yours.

• What do the individual subs look like on their own?
• Try processing the light subs without any calibration frames.
• Uninstall DSS and reinstall - it takes a very short time and you will return to default settings.

 

Edited July 17, 2020 by TerryMcK

[carastro]

I've not had time to download the calibration files as yet as I have an appointment and am going out in 10 minutes, so i just stacked the lights (I will do the calibration later).  

I left out a couple of subs which looked a bit washed out probably due to clouds, but this is the result of the lights only (just a quick process).  Stacked in DSS.  

This eliminates the light frames, so we'll see what happens later when I add the calibration subs.  

Carole 

 

Edited July 17, 2020 by carastro

[Guest]

Thank you @geeklee and @carastro.

I have stacked Comet Neowise but pretty certain I have done a preliminary stack on Bubble Nebula since then.

I have uninstalled and reinstalled @TerryMcK but still no joy - though I suspect the uninstall did not reset any settings as DSS remembered the last folders when browsing for subs and calibration frames.

[carastro]

I am at the Vets atm.  
But just to say l got some very odd results with a OSC camera some years ago.  Like a moire pattern.  It was concluded that there was something wrong with the Bayer pattern.  So just checking you have selected your Camera in DSS.  Although l think all Canon Cameras use the same  

carole 

[carastro]

Have you got another Computer you can do a fresh install and see what happens on there.  

carole

[tooth_dr]

I’ve had this happen to me. It was, if I remember correctly, due to the threshold detection in the settings before you start analysing.  I bet it’s too low and you are analysing noise as stars. 

[TerryMcK]

If you uninstall DSS it may leave the settings you have in the Windows registry. Indeed my settings are stored here Computer\HKEY_CURRENT_USER\Software\DeepSkyStacker

To delete them you have to run regedit (the Registry Editor)

Navigate to DeepskyStacker in the registry and right click it. Then select Delete.

When you subsequently reinstall the registry settings will be recreated with the default settings.

[Seelive]

I've had similar problems in the past, especially with Milky Way images.  DSS has successfully stacked some of my images with the threshold set at 2% (more than 40000 stars detected!) but on other images, even with the threshold set at a much higher value, I've still ended up with 'swirls' (at worst, or just elongated stars in one particular area at best) in the stacked images.  I've found that changing the alignment mode from 'Auto' to Bisquared or Bilinear cured the problem.  If you look in the stackinfo.txt file, you will see the stacking coefficients used for each image.  If you see any numbers (within the brackets next to the alignment method used for each image) much greater than 1 then the stacking is likely to have had a problem. Unfortunately, each number is to 20 decimal places and there are quite a few of them for each file!)

 

[carastro]

I have something very interesting to report. 

When I stacked the calibrated image I got this.  Without calibration (above it was fine).

One thing I did note was that I had to stack the darks and Bias as tiff and the lights as CR2, so whether that hass made a difference.  But I watched all the way through and it was applying flats darks and offset.

However I notice I had the wrong camera selected in the settings box, so am doing it yet again.  There is non Canon 600D listed in my version of DSS so I selected another DSLR.  I think they use the same Bayer Matrix pattern. 

Edited July 17, 2020 by carastro

[tooth_dr]

Same results as you carole, cant get it stack with calibration data

eg

[tooth_dr]

Exact same settings as above, but the calibration data unchecked:

[carastro]

At least it's not me, and it's not Chris either, but strange we are getting a different pattern.

Going to try without flats and then without darks and bias in rotation.

Interestingly I won't whether Chris is doing his Flats correctly as stretched they don;t seem to show any sign of vignetting or dust.  Though that shouldn't produce this sort of result, it would just come out as if no flats were applied.

Carole   

[tooth_dr]

1 minute ago, carastro said:

At least it's not me, and it's not Chris either, but strange we are getting a different pattern.

Going to try without flats and then without darks and bias in rotation.

Interestingly I won't whether Chris is doing his Flats correctly as stretched they don;t seem to show any sign of vignetting or dust.  Though that shouldn't produce this sort of result, it would just come out as if no flats were applied.

Carole   

I got your pattern to Carole, using different settings.

[carastro]

I am getting a proper image without the calibration:

This is what I get lights only:

 

 

[carastro]

Just doing a stack with no flats, actually deleted the flats file from the list.

Carole  

[tooth_dr]

When I loaded the files into APP, the flat came up as a 'mono' file according to the automatically applied header that APP reads.  I wonder if that the problem? I'm currently stacking the data in APP.

No matter what I try in DSS I cant get it to stack, even lights only.  Here is the one similar to yours.

Edited July 17, 2020 by tooth_dr

[carastro]

Weird.  

This is a stack with no flats, just darks and Bias, no nebulosity at all but no weird shapes.

 

[tooth_dr]

I loaded all into APP --> lights, flats, darks, bias --> and get this!

Thanks for sharing your data 👍