[Solved]Could this be an issue with my Oiii filter?

[jjosefsen]

Hi,

I'm working with some recent data of a new(ish) camera, and my Ha data is pretty good, but the oiii has these strange artifacts around the borders.

If I use any kind of local normalization then it pretty much ruins most of the image, as you can see below..

First the Ha:

 

Oiii with local normalization:

 

oiii local normalization map, see how it fits with the artifacts:

 

Oiii without any local normalization:

 

These edge artifacts, could they be related to a bad filter or is it a processing artifact, has anyone seen anything similar?

 

I am using Astro Pixel Processor for calibration and stacking.. Im kind of stumped on this one, and I am going to yank out the Oiii filter this weekend to have a looksie.

Edited August 30, 2019 by jjosefsen

[Xplode]

Can you see any of it on your raw images?

[geordie85]

It looks more like a stacking artifact due to field rotation during your imaging session. 

Have you tried cropping the edges before running normalisation? 

[jjosefsen]

3 hours ago, Xplode said:

Can you see any of it on your raw images?

No I can't. At least not in a normal stretch.

[jjosefsen]

31 minutes ago, geordie85 said:

It looks more like a stacking artifact due to field rotation during your imaging session. 

Have you tried cropping the edges before running normalisation? 

No - but I suppose I can do that somehow as a batch process.

It is just strange that it doesn't happen in my Ha stack as well.

[jjosefsen]

Problem solved!

It was due to stacking artifacts introduced by APP.

When those were resolved, the normalization issues were gone. :)