M31 - One Year Later

[Xiga]

Hi guys

Still no chance of getting any imaging done, so what better to do than revisit old data!

I thought I'd go back and re-do M31, as it is my longest data set (by quite some distance) for a true colour target. I usually only end up with a couple of hrs to work with, but on this occasion I was able to get 7 hrs worth, all on a single night with no moon about. Plus, I was never truly happy with how the original came out, but I kept putting off a re-process as I remember finding M31 an absolute beast to process at the time!

24 x 300s with an IDAS-D1 (ISO 200)

51 x 360s with an IDAS-D1 (ISO 200)

Nikon D5300a

SW 80ED, w FF/FR

HEQ5-Pro

Captured with Sequence Generator Pro, Calibrated and Stacked in Astro Pixel Processor, and processed in PS.

The main difference this time, was I was able to deal with the stars properly (this time last year I clearly hadn't a clue, lol). I also did a Bayer Drizzle stack this time, as I had so many subs to work with, and it seemed to bring out some finer scale details.

I used a new processing technique which I came up with (i'll try and post a thread on it when I get a chance), but basically it involved using 2 layers - the bottom layer was a lightly arcsinh-stretched one (mainly for the stars, but it also still contains sky background and nebulosity), and the top layer was a starless one (made in Starnet++) but with the blend mode set to 'Screen'. With further Curve adjustments to both layers, it was possible to push the nebulosity but keep the small stars shining through, and without dark halos. So the image below has had no star reduction applied. More experimentation needed on this one though.

Oh, I also flipped it horizontally this time (not sure if that's a faux pas!). I prefer this orientation, but then again it could just be because my brain thinks it looks more interesting by virtue of just being different.

C&C welcomed (I have a tendency to push my images just over the edge if i'm being honest) so i'm always on the lookout for feedback.

CS!

https://astrob.in/373639/H/

 

ps - Here's a link to the (now clearly awful) version from last year for reference.

https://astrob.in/373639/0/

Edited December 12, 2019 by Xiga

[Adreneline]

What's to say? How about awesome!

Adrian

Edited December 12, 2019 by Adreneline

[Rodd]

This is one of the best M31 images I have seen.  I can almost see it spiraling around, sloshing like a giant world-pool. 

Rodd

[Allinthehead]

Wonderful. That's a remarkable improvement on the original. 

Starnet is a great tool to have. I use it on every image now. Makes for tiny stars.

[Xiga]

9 hours ago, Adreneline said:

What's to say? How about awesome!

Adrian

Thanks Adrian!

5 hours ago, Rodd said:

This is one of the best M31 images I have seen.  I can almost see it spiraling around, sloshing like a giant world-pool. 

Rodd

Wow, thanks Rodd! 

I think some of it is down to the orientation. It was only at the very end of the workflow that i decided to flip it, and the impact was immediate. Straight away it just looked way better! So i just went with it. 

 

4 hours ago, Allinthehead said:

Wonderful. That's a remarkable improvement on the original. 

Starnet is a great tool to have. I use it on every image now. Makes for tiny stars.

Thanks Richard.

So it sounds like i may have, by chance, just stumbled across a similar workflow to yourself. This is most pleasing, considering the standard of your work! As you say, Starnet is truly amazing. Up until this image, i had only ever considered using it on NB images. Not any more. It's going to get used a lot from now on! 🙂 

[tooth_dr]

Yes this is totally stunning.  The spiral structure is better than I've seen before.  Looks almost like it's moving.  I would really like to see your workflow - if I get 20% as good as this I'll be happy.

[Laurin Dave]

Excellent … and a quite remarkable amount of colour for a DSLR.. well done.. and it does seem to be moving!

Dave

[Xiga]

4 hours ago, tooth_dr said:

Yes this is totally stunning.  The spiral structure is better than I've seen before.  Looks almost like it's moving.  I would really like to see your workflow - if I get 20% as good as this I'll be happy.

Thank you Adam. I have to admit it did come out a lot better than I was expecting myself. Being a PS user, my workflow can be a bit all over the place tbh, lots of micro-decisions being made constantly, so hard to nail it down exactly, but I will try and post up a rough guide on the Image Processing forum over the weekend.

[Xiga]

4 hours ago, Laurin Dave said:

Excellent … and a quite remarkable amount of colour for a DSLR.. well done.. and it does seem to be moving!

Dave

Thanks Dave! It must be whatever I did with the dust lanes that gives it the impression of moving, lol. I suppose it does have a certain 3D feel to it.

As for colour, I've always found the D5300 very easy to deal with in this regard. Because it effectively has an ISO-less sensor, it means I can shoot everything at ISO 200, which gives me loads of Dynamic Range to work with, but still with very low read noise.

It really is a brilliant camera for all it costs. Even though I have a (new to me) Qhy163c sitting in a box, still unused, I somehow doubt I will ever love it the way I do the wee Nikon 😀

[teoria_del_big_bang]

Fantastic image 🙂 

Steve

[Xiga]

11 hours ago, teoria_del_big_bang said:

Fantastic image 🙂 

Steve

Thanks Steve! 🙂 

[Xiga]

So is no-one bothered by the fact it is in reverse? I had assumed it would upset a few purists (i might be one of them myself tbh!).

For comparisons sake, i've flipped it back to the traditional framing below. But comparing the two side-by-side, i don't know why, but i definitely prefer the flipped one. This confuses me, because i have certainly looked at hundreds of pictures of M31 over the years, so my brain should be naturally attuned to seeing it framed 'correctly', but for whatever reason, i find the dust lanes and overall shape of the galaxy so much more aesthetically pleasing in the flipped one. 

I put myself marginally in the 'pretty picture' camp when it comes to AP, so i'm inclined to just leave it as it is and stop thinking about it. 

What do others think. Am i just imagining things? 🤔

[tooth_dr]

@Xiga I think you might be onto something.  M31 to me just seemed to be lacking something in terms of ‘depth’ when I looked at it. Yours looks just that bit different 👍🏼

[carastro]

Quote

So is no-one bothered by the fact it is in reverse? I had assumed it would upset a few purists (i might be one of them myself tbh!).

Yup it bothered me but it's a fabulous result with excellent colour, can't believe this was done with a DSLR.  Looking forward to see the details of your new technique posted up.

Carole 

Edited December 14, 2019 by carastro

[Ceph]

Thats a beautiful M31 well done

[Xiga]

On 14/12/2019 at 08:17, tooth_dr said:

@Xiga I think you might be onto something.  M31 to me just seemed to be lacking something in terms of ‘depth’ when I looked at it. Yours looks just that bit different 👍🏼

Thanks Adam. It's still not sitting right with me though. I know it's ok to rotate images any way we want, but deep down i know that inverting them is kind of 'out of bounds'. 

Sure i have both versions saved, so i can pick and choose as i like, lol. 

 

On 14/12/2019 at 08:33, carastro said:

Yup it bothered me but it's a fabulous result with excellent colour, can't believe this was done with a DSLR.  Looking forward to see the details of your new technique posted up.

Carole 

Than you Carole! Colour is rarely a problem with the D5300. I think most DSLR users are still using the earlier Canon's, which have much lower DR due to the need to use them at higher ISO's. Whereas the D5300 can be used at ISO 200, which gives tonnes of DR to work with. 

I meant to post something about the workflow over the weekend, but never quite found the time. I will try and do so at some point during the week. 

9 hours ago, Ceph said:

Thats a beautiful M31 well done

Thanks Ceph! 

Edited December 17, 2019 by Xiga