M81

[hollow ember]

M81

C9.25 with .63 reducer
Fl 1335
Oag with 120mm
585mc pro with uv/ir cut
Bortle 9
1155x30 seconds - 9.6 hours

Both nights were processed with
100 dark, 100 bias, 100 flat

Any idea what causes the black bar on the bottom?

This is my first time processing such a large data set. I collected 1540 exposures and stacked the best 75% weighted (going to try again with 60% to see if its any better)

Open to any improvement ideas

Processed in siril

[tepid shoal]

Well framed.
It seems like your flats didn't work. With 100 flats I'd say this is overkill. 40 flats should be good enough for astrophotography unless your taking flats per filter.

Have you just stacked your images without calibration frames and worked out if this is cause of the black line?

You can also give Seti Astro Suite a go and see if your able to get a better result.
I'd also be willing to process and see what I can do or you can post in the "share your data" section of this group.

[hollow ember]

Thanks. I was leaning towards flats being the issue. I tried using a new method for flats with a light panel but the panel just barely coverers the entire area. I need a slightly larger light panel.

Good to know 100 is over kill. I will try a new stack to rule out if flats are the issue.

That would be great if you could give it a go! Thanks. I will share it out.

[tepid shoal]

Yes I think you have found the issue. You hlcan resort back to using a white t-shirt for flats or you can shoot your flats in the daytime whilst pointing your scope at a white peice of papper that's attached to a fence / wall. Just make your sure don't have any light leaks.
I do believe that 40 flat's will be enough.

Highly recommended to stack without the flats.
As for the dark's I haven't found with my uncooled 585 that, darks don't help that much but this is dependant on your location and shooting temperatures.
I recently modded my uncooled 585 so it's now a peliter cooled camera, it worked very well as I was hitting between 7/8 degrees below ambient temperature.

You have some decent data in your image. With the better software we have in recent years you should be able to get a decent result.

This is my edit from my phone using Lr mobile.
Hope you don't mind me trying.

So the data IS THERE. 😊

[hollow ember]

Thanks. I just posted this stack in share your data if you want to try that out

That is cool you modified your cam.

[hollow ember]

Would it be worth running the preprocessor on only 40 darks/flats/bias Instead of 100?

[tepid shoal]

Will have a look tomorrow at some point. Thanks.

[tepid shoal]

No, I doubt it. Probably best to not include any flats. Just run a decent background removal tool like GraXpert instead.

[jovial spindle]

Bortle 9 is rough. Broadband is pretty much off the table. 9h made for okay data but this would be on a completely different level if you went to a bortle 4 or 3

If you want to stay in a bortle 9 look into narrowband

[hollow ember]

Thanks. Nice edit.
Yeah b9 is brutal.

I made a new stack of 60% best frames and it didnt have that black bar on the bottom.

[hollow ember]

Was your edit from my png or from the stack.fit?

[jovial spindle]

From the .fit

[astral coral]

Very cool

[hollow ember]

Tried a full new processing on the orginal stack from this post. I didnt get the black bar this time.

[hollow ember]

What program did you use for this? How do you get all that color out of it?

[jovial spindle]

Pixinsight. Used a mask to select only the galaxy and then increased saturation. I couldn’t push the saturation nearly as far as I wanted to because of that purple halo

[hollow ember]

Version 4.
Still noisy but getting there