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2022-05-29: APP 2.0.0-beta2 has been released !

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ASI2600mc Pro vertical lines after stack


(@herm66049)
Molecular Cloud Customer
Joined: 1 year ago
Posts: 5
Topic starter  

 

MARK CHAIN ASIstudioStack PS St4 AstTools   Copy
MarkChainD ls St APP

I have used APP successfully with my Canon 600D and 80D, and recently began using a new ASI2600mc Pro to image Markarian's Chain.   After taking 60 lights of 120 seconds, gain of 100, cooling at 32F, and stacking there are three vertical lines that appeared.  I then tried a second stacking that included 30 dark frames with the same result.  Also in the image the stars and galaxies appear to have become horizontally elongated with some double images.

I then stacked the same images in the ASIStudio software, and in the included image it can be seen there was no vertical banding or elongated stars and galaxies.

I'd appreciate thoughts as to the cause, and hopefully a solution to the problem.  I'd prefer to stay with APP, rather than ASIStudio at this time.  Hopefully two images appear.

MarkChainD ls St APP
MARK CHAIN ASIstudioStack PS St4 AstTools   Copy
MarkChainD ls St APP
This topic was modified 3 months ago by Jeff Herman

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(@vincent-mod)
Quasar Admin
Joined: 5 years ago
Posts: 4830
 

Mmm, difficult one. The APP result at least has a better histogram, the Asi studio stretch looks really weird and all data is well clipped into the background, so I can't compare them really as they are very different. Maybe due to the issue in the asi result, you can't now see the artifact, but the data doesn't look ok either.

image

 


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(@herm66049)
Molecular Cloud Customer
Joined: 1 year ago
Posts: 5
Topic starter  

If the ASIStudio image is ignored, what would explain the vertical lines, and double stars in the APP stack image?   


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(@vincent-mod)
Quasar Admin
Joined: 5 years ago
Posts: 4830
 

Good question, but I suspect a data issue. Maybe you can upload like 10 lights, 10 flats, 10 darks and 10 bias/darkflats for me to investigate?


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(@herm66049)
Molecular Cloud Customer
Joined: 1 year ago
Posts: 5
Topic starter  

I've sent 10 of 86 light FITs files of the Leo Triplet that I used to stack the image that I've also included.  This is from an imaging session after the original Markarian Chain session that I originally asked you about.  As you can see there is remarkable vertical banding and double images with this stacked image, also.  They are in the folder below, as you requested.

Oddly enough, between these two sessions I imaged the Jellyfish nebula with no issues what so ever.  Same camera, scope, mount, but did use the Optolong L-Enhance with the Jellyfish.

herm66049-stripedResult

Best,

Jeff


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(@herm66049)
Molecular Cloud Customer
Joined: 1 year ago
Posts: 5
Topic starter  

I forgot to mention that I only had lights.


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(@vincent-mod)
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Joined: 5 years ago
Posts: 4830
 

Hi Jeff,

Apologies for not getting back to you, I was struck by human malware. I'll try to have a look today or tomorrow.


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(@vincent-mod)
Quasar Admin
Joined: 5 years ago
Posts: 4830
 

So, other then I think that there may be some underexposure going on, I don't see other issues with the lights. So you don't have any calibration files?

image

Looking at the tif file you included, that to me looks a lot like a data transfer issue. Are you processing on your internal SSD or harddrive?


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(@herm66049)
Molecular Cloud Customer
Joined: 1 year ago
Posts: 5
Topic starter  

Only lights, since this was the first and third target I captured with this new ASI2600mc Pro.  From APP, I had been accessing the  data directly from a USB thumb drive.  After your suggestion, I moved the data from the USB to a folder on the PC desktop, and then accessed it using APP.  The result was an image without lines, so I think your data transfer issue suggestion is correct.  Thanks for the help.  

I like the ASI camera, but I've been disappointed with the support and suggestions for a good work flow.  Specifically the need for calibration frames (or no need), and which ones to use.  There are many online suggestions, but many of them are conflicting.  If you'd be willing to offer a suggestion (or point me in the direction of a forum thread that would be helpful) for which calibration frames are appropriate, I'd appreciate it.

Best,

Jeff


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(@wvreeven)
Galaxy Admin
Joined: 4 years ago
Posts: 1718
 

@herm66049 Jef, for APP it is advisable to use flats (for dark pixel detection and correction of dust and vignetting) and darks or a bad pixel map (for hot pixel detection). My wife and I use an ASI2600MC and an ASI6200MM. And we shoot with AAP as well.

AAP fixes the offset of all images (light, dark, flat, etc) so that's one degree of freedom less to worry about. We have shot darks (60 s.) and dark flats (2 sec) for gain 100 (which we always use) and the temperatures -10ºC and 0ºC (we use 0ºC most since that works well in our climate). From these we created two master darks, two master dark flats and a bad pixel map which we always use. Since our flats usually and our lights occasionally are not exactly 2 sec resp 60 sec, we also shot 200 bias at the shortest exposure time (0.001 sec) and the temperatures -10ºC and 0ºC. Those we used to create the master darks and dark flats. With those masters and the bad pixel map, APP can process all our flats and lights since it now can extrapolate the master darks and master dark flats to the exposure times used. We usually load all of them to be on the safe side.

 

HTH, Wouter


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