18 Hours on the Leo Triplet

[WolfieGlos]

This is my first image for a while, helped by combining data captured in 2023 with some from this year 🙂 I captured just over 5 hours on this one with my (relatively new at the time) Starfield 102 in late May 2023, which was after the loss of astro-dark time.

My intention was to return to it this year, gather more data and try to capture the tidal streams, especially from NGC 3628. Despite the weather this year, I've managed to capture an additional 13 hours over 4 sessions, to bring this up to a total of 18:35:00.

Whilst I have managed to capture the tidal stream which was visible after "only" 12 hours, despite adding another 6 hours this weekend it's still faint and noisy. I wouldn't usually have the background this bright (to mask the DSLR noise) but it's the only way I can show it! Still, I managed to get the streams around M66 and some detail in M65 too.

One of the hardest ones I've processed, primarily due to balancing the faint tidal streams with the bright cores of the galaxies. Numerous attempts lost the core details or ended up with a horrible background. Suspect I may be missing some tricks in my processing toolkit and knowledge - forever learning! - but I think I got there in the end.

2023 subs = 83x180s + 2x150s + 31x120s , 2024 subs = 247x180s, 29x120s. Different sub lengths due to some Moon affected nights.

Starfield 102 with 0.8 reducer + Canon 800Da (no filters). Stacked in ASTAP, processed with Siril, GIMP, Starnet and Topaz.

Comments / criticism welcome 🙂

Revised version processed with PI and Blur/Noise XT.

Revised version below following feedback:

Original version below:

Edited April 23 by WolfieGlos
PI process added

[Mr Spock]

Lovely image quality 👍

[tomato]

Great detail in the galaxies and the faint stuff is there too.👍

I have only viewed it on an iPad but there is hint of red in the background?

[fwm891]

Well done. Agree with @tomato about the redness. I would also lighten the background too that will help you bring out the tidal effects more.

[wookie1965]

Cracking image 

[ollypenrice]

9 hours ago, fwm891 said:

Well done. Agree with @tomato about the redness. I would also lighten the background too that will help you bring out the tidal effects more.

This! I'm sure you have discarded, through black clipping, many of the benefits of your heroic 18 hour run on this target. Lightening the background of this version won't help because, when it's gone, it's gone. But if you go back to the linear and pay great attention never to black clip, I'm sure you'll find oodles of wonderful faint stuff in your data. The histogram never lies:

Olly

[WolfieGlos]

On 02/04/2024 at 04:01, Mr Spock said:

Lovely image quality 👍

Many thanks Michael 🙂

On 02/04/2024 at 09:47, wookie1965 said:

Cracking image 

Thanks wookie ! 

On 02/04/2024 at 08:55, tomato said:

Great detail in the galaxies and the faint stuff is there too.👍

I have only viewed it on an iPad but there is hint of red in the background?

Thanks Steve, 

On 02/04/2024 at 09:01, fwm891 said:

Well done. Agree with @tomato about the redness. I would also lighten the background too that will help you bring out the tidal effects more.

 

19 hours ago, ollypenrice said:

This! I'm sure you have discarded, through black clipping, many of the benefits of your heroic 18 hour run on this target. Lightening the background of this version won't help because, when it's gone, it's gone. But if you go back to the linear and pay great attention never to black clip, I'm sure you'll find oodles of wonderful faint stuff in your data. The histogram never lies:

Olly

Thanks Steve, Francis and Olly. It must be my monitor, since the red wasn't so obvious when I processed it, but now I see you are absolutely correct on this (different) monitor. Moreover, it's redder than if I look on the phone/tablet (!) so will definitely look into this. Much appreciated.

@ollypenrice regarding the black clipping, I did lower it right at the end of processing, previously the histogram was further to the right. Just prior to this, I removed some colour noise in the background (which I think came in from the noise reduction, as it horrific when stretched) using an LCH Colour Overlay, and this might also explain the redness in the image. It's not something I have to use often, and I did this at the wrong step in the workflow with hindsight.

Edited April 3 by WolfieGlos

[WolfieGlos]

Well here's another attempt, processed from scratch using the same stack.

This time I managed to keep a lighter background as suggested @fwm891 and @ollypenrice.

This required a lot more processing steps than I care to count, but I managed to get more of the tail showing. Despite the hours put into collecting the data, I seemed to be hampered with a poor background and blotchy areas, which I suspect is a combination of high-level cloud and DSLR noise / noise reduction software. Whatever the source, I managed to rectify a blotchy background by using GIMP's gradient tool as a final step, which seems to have worked very well.

Thanks for the input chaps, comments welcome as always 👍

[ollypenrice]

Much better background and now you have that tail showing decisively.

Olly.

Edited April 4 by ollypenrice
typo

[900SL]

Excellent image Wolfie. I'd be delighted with that!

[WolfieGlos]

Thanks @900SL 🙂

[WolfieGlos]

Final process, I promise!

Given that it's a very recent image, I decided to give this the PI and XT treatment now that I'm full on learning this software. Noise has gone, tidal tail from NGC 3628 more visible and, to my eye, a better colour balance. Comments welcome as always 🙂

 

 

[geeklee]

8 hours ago, WolfieGlos said:

Final process

Another very good revision Chris - they've definitely all had their clear merits, with an incremental change along the way. I do prefer the colours here although just personal preference.  Great job with the tidal tail on NGC 3628.

Any other commentary & feedback is just of the pixel peeping variety - I won't bore you with that