M101 - please critique

[LuckieEddie]

Hi all,
Here's my first effort with enough patience to get a reasonable total exposure time - just under 4 hours after I'd filtered out the worst subs.
Please point out what you think I could improve in my processing, which is exclusively in Siril and GIMP.
Sky was Bortle 6 (according to Clear Outside) but there's loads of local lighting surround me. I had lots background gradient to remove.

M101

 

Edited March 23, 2021 by LuckieEddie
Tried different image attachment method

[CraigT82]

Thats a really nice effort, well done. First thing I noticed though was the background sky was totally black (black point has clipped off some of the data) which does make the target object stand out but you are wasting some of your hard earned data by doing that. 

[LuckieEddie]

Thanks Craig. I did deliberately push the blacks down to help squash the noise but I think the compression that SGL's applied to the image is what's actually completely clipping it. If I zoom right in on the uncompressed version in the link I can still see faint noise. I was having some trouble getting a link to show an image in this forum, maybe I've still not got it right.

[tomato]

First off, that’s a fine M101, nicely framed, focused and round, tight stars. Good colour and detail also. I’d agree that the data looks black point clipped, maybe you were tempted to do this to remove gradients, but as @CraigT82 has pointed out, this loses some of your hard earned data.  At 4 hrs integration from a middling sky, there will still be some noise present, but a stronger stretch will show the fainter regions. I think some more data would give you more options when processing, this is well on the way to being a M101 an experienced imager would be proud of.👍

[david_taurus83]

Is it just me or is the forum not loading the image properly? If I click on it though I get this:

 

Anyway, some nice spiral detail there! It's not an easy target so we'll done, I say!

[tooth_dr]

31 minutes ago, david_taurus83 said:

Is it just me or is the forum not loading the image properly? If I click on it though I get this:

 

Anyway, some nice spiral detail there! It's not an easy target so we'll done, I say!

I would have said it was too dark, but like you when I clicked on it, a brighter version appears.

[teoria_del_big_bang]

Very odd, when you click on the image it really does become a very good image indeed.

This is an excellent image:

Steve

[tomato]

Yes indeed, the click makes all the difference! It’s now an excellent M101.

[Laurieast]

Top image is a PNG , clicked on version is JPG?

[LuckieEddie]

I've just editing the original post to try attaching the image in a different way. Hopefully that's cleared it up.

Anyway, thanks for all your positive comments on the image (once correctly displayed!) I'm very encouraged.

So, my immediate takeaways are: You can never have too much total exposure time, and I need to learn more about how the forum works. 😉

[alacant]

15 hours ago, LuckieEddie said:

under 4 hours

Lovely shot. The 200p is perfect for galaxies.