Markarian's Chain (DSS help?)

[SiriusDoggy]

Hey guys, I'm fairly new to DSO imaging and was testing my gear in my very light-polluted backyard to make sure everything is talking to all the hardware and software. I decided to go for this shot because of it's position in my limited field of view but I'm curious if anyone can help me troubleshoot the black bar across the top of the image. It doesn't show up in any of my individual subs, darks or lights.
Here's what I did. Again, I was just testing gear and software so I'm not expected an APOD here but would like to improve.

ZWO 1600mm cooled camera (But cooling was NOT turned on. Again, just tested hardware and software, I know the cooler works)
StellarVue SV70T Scope.
Captured as 30 second subs in SharpCap Pro - (8bit FITS) I know, should have been set to 16bit.
I captured 60 subs, 30 darks and 30 lights and ran it through the default settings in DSS
Opened it in Photoshop and adjusted levels and curves and discovered the horrible black bar across the top.

Any ideas?

[wornish]

Can you share one of the individual lights?

You say you are in a light polluted location, it could be a shadow from something.

[SiriusDoggy]

I thought that might be the case. There's plenty of lights shining around in my neighbor's yards. After careful looking this morning with clear eyes, it does appear to be on many, if not all, of the individual frames. It seems worse in some.

At least that solves the question of if it was caused by the individual files or the DSS processing.

Here's a link to one of the FITS files.

https://drive.google.com/file/d/1EoG5D8tyQHGmFjAZOb1cz9SbpQ5QPDG9/view?usp=sharing

[wornish]

I tried over stretching in Pixinsight but there is no sign in the sub you shared it looks fine.

If you can see it on some of them you have answered your own question.

Inspect each one and discard the ones showing the shadow.

 

 

[SiriusDoggy]

4 minutes ago, wornish said:

I tried over stretching in Pixinsight but there is no sign in the sub you shared it looks fine.

If you can see it on some of them you have answered your own question.

Inspect each one and discard the ones showing the shadow.

 

 

That's interesting, because I picked that file because I could easily see it in that file. Maybe I picked the wrong file. If you don't mind, could you look at this file and see if it's there?

https://drive.google.com/file/d/1nG2liqIhu94wXEEeCFgWodbPuLPk6meJ/view?usp=sharing

[wornish]

Its certainly in the second one see attached image.

 

And I just retried the first and it is there as well although less noticeable.

 

Edited April 19, 2020 by wornish

[SiriusDoggy]

Ah ha! I must have accidental selected one of the good frames the first time around. Thanks for checking that for me Dave.

[happy-kat]

As a thought what if you select your best frame with no band as the reference file and then use kappa clipping on stacking.

[SiriusDoggy]

I'll give that a try. Thanks guys for all the help and suggestions. I only get out about once or twice a year for DSO's so this stuff is not second nature for me.