Geometric shapes in integration results

Hi @mountainair,

That looks really weird, can you share the fits headers with me? The info is shown in the metadata/header window to the left of the image viewer 😉

Mabula

Hi Mabula,

This has been reproducible with other targets as well.  It never happens when I stack lots of frames.  It seems to be worse with small numbers, like: 

2 frames - strong effect

3 frames - no effect

4 frames - effect

5 frames - no effect

6 frames - less effect

7 frames - no effect

8 frames - no effect

9 frames - no effect

10 frames - no effect

Here is what two stacked frames look like -- the effect is even stronger:

I have attached the FITS headers from the stacked result as well as the 2 individual subs that went into this.

Also, I am adding dynamic distortion correction to 4/registration, changing mode to advanced in 5/normalization and enabling 1st Degree LNC/3 tier and 5% MBB in 6/integration.  Those are the only changes.  Master flats, master dark flats, master darks and BPM used.

Note:  This is still occurring as of Beta 23.  It's not a killer, given it's rare to stack so few frames, but that's all I could get out of the supernova in NGC 1097 last night.  

@mabula-admin I have uploaded the subs I used, the integrated results, and the RGB-combined result to /AstroPixelProcessorUpload/MountainAir-geometricartifact on FileStation.

As I mentioned, this is likely lower priority.  In both these cases I tried to sneak in targets between other targets and ended up with a small number of subs -- in this case a ridiculous two for B and G and only one for R.

If this isn't worth fixing (it seems to go away entirely when you get to 7 subs per integration or more), perhaps just pop up a warning to users who try to generate integrations from a small, even number of integrated frames.

Hello all. I have put my integration in the folder in File Station. If you look at the header of the fit file, you can see my integration settings. The artifacts come from the Automatic mode in Tab 6. With so few images, Median is selected as the Rejection method and that creates the Geometric artifacts. You have to select Manuel Average in Integrate Tab 6, then everything works as expected. The hotpixels can be removed with Cosmetic Correction, at least most of them.

Hope this helps.

@mountainair & @minusman

Thank you very much for reporting this and your testing. It is something that definitely should not occur for sure, so I will test this and fix it 😉

I guess the combination here of both median and MBB causes this. Or does it also happen with MBB turned off? ( I will test myself of course 😉

Mabula

Hi Mabula, I can confirm that when MBB is deactivated the edges look fine.

With best regards.

Thanks @minusman for checking 😉

I will test and fix for sure !

Mabula