M31 HaLRGB

[Rodd]

My first real attempt at M31.   No Ha yet, though I plan to add it.  I can't say I love the palate, which is strange because the histogram is perfectly balanced, but I do like the detail and the color of the stars  Ha will help a bit--but not with the blue stars  that should be quietly glimmering along the spiral ridges.  Any advice would be most welcome.  I am sure I will be tweaking this, and no doubt recreating it from scratch, for the next few weeks.

FSQ 106 with .6x reducer and ASI 1600.

L 120 30sec

Red: 115 30sec

Green: 100 30 sec

Blue: 128 30 sec

 

 

[Sunshine]

Wonderful image of Andromeda right there!

[wornish]

Great image.  

 

With the FSQ and the reducer what F number are you effectively at, and what gain were you using on your ASI 1600  to get 30 sec exposures?

I plan on doing this myself  on the next clear sky night here with my new ASI 1600MM. 

[Rodd]

8 hours ago, Sunshine said:

Wonderful image of Andromeda right there!

Thanks Sunshine

Rodd

[Rodd]

2 hours ago, wornish said:

Great image.  

 

With the FSQ and the reducer what F number are you effectively at, and what gain were you using on your ASI 1600  to get 30 sec exposures?

I plan on doing this myself in on the next clear sky night here with my new ASI 1600MM. 

Thanks Dave.  With the .6x reducer the FSQ 106 shoots at F3.  So far I have just used unity gain (139).  I have found exposure times are target dependent.  I used 60sec Ha and OIII subs for the veil, but needed longer subs for the fainter Sh2-119.  30sec broadband worked well for M8 and m20, as well as this target, but the faint NGC 7822 requires longer subs--90sec to 2min, haven't dialed it in yet.  I am still getting a handle on exposure times.

Rodd

[Stub Mandrel]

Nice image with lovely details, especially the crisp dust lanes.

The blue stars look as if affected by CA, which shouldn't be an issues with RGB imaging, but with so many blue stars you should be able to see the blue areas in the galaxy. I think I can see faint traces of the blue areas. Could it be you have overstretched the blue layer trying to get the star-forming areas, bloating the stars? Perhaps protecting the stars and bringing out the blue star-forming areas will work?

I'm no expert but I have found it takes a LOT of playing to get nice colours from Andromeda and I'm far from satisfied with any of my attempts.

By the way many of the 'stars' close to Andromeda are actually globular clusters around the galaxy - I think it's amazing to image DSOs in another galaxy!

 

[Rodd]

35 minutes ago, Stub Mandrel said:

Nice image with lovely details, especially the crisp dust lanes.

The blue stars look as if affected by CA, which shouldn't be an issues with RGB imaging, but with so many blue stars you should be able to see the blue areas in the galaxy. I think I can see faint traces of the blue areas. Could it be you have overstretched the blue layer trying to get the star-forming areas, bloating the stars? Perhaps protecting the stars and bringing out the blue star-forming areas will work?

I'm no expert but I have found it takes a LOT of playing to get nice colours from Andromeda and I'm far from satisfied with any of my attempts.

By the way many of the 'stars' close to Andromeda are actually globular clusters around the galaxy - I think it's amazing to image DSOs in another galaxy!

 

Thanks Neil.  I appreciate your thoughts.  Yes, I can see faint blue regions too--I didn't really stretch the blue--just stretched everything after combination.  The histogram is pretty even.  Maybe 80min total exposure for blue is just not enough data to portray the faint colors?  Not sure.  I could try a color mask--but I don't have that script on this computer--its the new edition of PI.  I have it on my other laptop.  But the blue areas are so faint the script probably won't pick them up.  I have limited success with the color mask script.  I plan to add Ha as soon as I get a clear night.  That should add some color top the image.  I will reprocess from scratch to get the HaLRGB and maybe I will be able to do as you suggest and bring out the blue stars.  I suppose I could collect more blue subs--maybe longer subs?  Sometimes it counter intuitive though.  Sometimes I will have an image that is blue deficient (I only collected 10 blur subs) and yet blue dominates the histogram.   That would make sense if the histogram portrays noise as well as signal.  It may be that the blue is spot on and the other colors are overshadowing it--the image looks a bit red/pinkish to me.  I tried reducing red and green to various extents and that wasn't the answer though.  I find fooling around with broadband palette is a slippery slope to cartoon land anyway.   You are definitely right though about needing allot of work to really get decent colors--the devil's in the details and the tiniest detail can have a big impact of the image, especially cumulative effects--hence the insane amount of settings in PI tools!

Rodd

[Stub Mandrel]

I had a play in PS with the low res version above.  Colour balanced with gardient exterminator. Removed large and small blue violet haloes, to stop the stars getting overblued later. Put a temporary maximum saturation layer on that showed the blue clouds were devoid of any blue at all - in fact they were magenta, so a push from red towards blue/cyan needed! Bullied the colour balance taking care not to get too green then removed the saturation layer and used more subtle saturation enhance - probably overdone....

[wimvb]

Great image, and excellent rework of the jpeg by @Stub Mandrel.

An apo of TAK standard shouldn't have CA, but f/3 may be pushing it. Do you refocus between filters? Chromatic aberration is just light of different wavelengths coming to focus at different positions. Refocusing between filters should solve the issue. (But not for the current image, of course).

In PixInsight, create a star mask and desaturate only blue, with the colour saturation process. This may be easier than color mask, which also captures any blue in the galaxy.

[Rodd]

1 hour ago, Stub Mandrel said:

I had a play in PS with the low res version above.  Colour balanced with gardient exterminator. Removed large and small blue violet haloes, to stop the stars getting overblued later. Put a temporary maximum saturation layer on that showed the blue clouds were devoid of any blue at all - in fact they were magenta, so a push from red towards blue/cyan needed! Bullied the colour balance taking care not to get too green then removed the saturation layer and used more subtle saturation enhance - probably overdone....

Yeah--I have to go back to the drawing board.  Thanks.  Ther eis blue around some stars, so I know the sensor is picking it up

Rodd

[Rodd]

1 hour ago, wimvb said:

Great image, and excellent rework of the jpeg by @Stub Mandrel.

An apo of TAK standard shouldn't have CA, but f/3 may be pushing it. Do you refocus between filters? Chromatic aberration is just light of different wavelengths coming to focus at different positions. Refocusing between filters should solve the issue. (But not for the current image, of course).

In PixInsight, create a star mask and desaturate only blue, with the colour saturation process. This may be easier than color mask, which also captures any blue in the galaxy.

I do refocus between filters.  I'll keep at it

Rodd

[tomato]

That’s a stunning image Rodd. Stub Mandrel has pulled more blue out in the galaxy, here is a version I processed with free data offered by Deep Sky West, not dissimilar to your image.

[Rodd]

34 minutes ago, tomato said:

That’s a stunning image Rodd. Stub Mandrel has pulled more blue out in the galaxy, here is a version I processed with free data offered by Deep Sky West, not dissimilar to your image.

Looks good.  I am thinking maybe add 60 sec or 2min subs.  Not sure what to do.  Even the best processors can only pull a wee bit more blue out of mine--so i think its in the data.  maybe 30 sec subs are just not cutting it.  But there is allot of blue in the Milky way stars.  Not sure!

Rodd

[ollypenrice]

Great job on the core, Rodd. I wouldn't go too far in pushing the colour though. I don't think this galaxy is a blaze of colour, really, and I feel I pushed my own version too far. However, I did get a similar red-blue distribution.

Olly

Edit: thre is also a very faint and highly extended outer glow which, with CCD, I found needed 30 min subs to pull out. Not sure how you'd go after this with CMOS.

[tomato]

I'm looking at these on a decent monitor at work (in my lunch break, boss, honest!) and I must say I now prefer the first rendition, something to do with the contrast on the dust lanes?

[Rodd]

7 hours ago, ollypenrice said:

Great job on the core, Rodd. I wouldn't go too far in pushing the colour though. I don't think this galaxy is a blaze of colour, really, and I feel I pushed my own version too far. However, I did get a similar red-blue distribution.

Olly

Edit: thre is also a very faint and highly extended outer glow which, with CCD, I found needed 30 min subs to pull out. Not sure how you'd go after this with CMOS.

Thanks Olly--you have a way of soothing ones anxieties.  I will add Ha though.  I think to pull out that glow I would need longer subs--probably 10 min at f3 with the cmos--but that may require HDR comp  due to the blown core--so an entire reprocess of several different exposure lengths for each filter.......I think that is for another attempt.  Hmmm.

Rodd

[Rodd]

3 hours ago, tomato said:

I'm looking at these on a decent monitor at work (in my lunch break, boss, honest!) and I must say I now prefer the first rendition, something to do with the contrast on the dust lanes?

Thanks Tomato/Tomaato I don't think the images posted by others were meant as final versions--just demonstrations about color and the composition of the palette.  I appreciate your dedication to work!

Rodd

[kirkster501]

My own versions of this galaxy are very similar to your first image Rodd, not mega colourful with a slight pinkish cast.

[Rodd]

2 hours ago, kirkster501 said:

My own versions of this galaxy are very similar to your first image Rodd, not mega colourful with a slight pinkish cast.

I guess I can live with it--there is a faint blue in regions where its expected.  maybe when I add the Ha the counter point of red-blue will work to bring the blue out a bit.  Maybe I will find a little tweak that gives the blue a boost.  We'll see.

Rodd

[Rodd]

I added 37 5min Ha subs.  Its a reprocess from scratch, so parts of the image did not come out as well, and parts better. Overall, I like the addition of the Ha.  I am not sure the image is finished yet--but I seem to have reached a a good stopping point for now.

 

 

 

 

 

 

[Rodd]

I had botched the previous attempt--not eth red smudge just off center.  Not a bad flat--I forgot to rotate a mask.  anyway....I had to have another go at it.  Corrected that issue.  Slowly moving incrementally toward improvement.  Maybe 30 sec subs are beginning to reveal their limitations however (a.k.a.  no Geuggenspiel shine--or what ever Olly mentioned).  But at least a bit of blue is starting to peep around the ends of the spiral arms.  2 versions...saturation is the variable

 

[toxic]

lovely image Rodd and the HA version 

[Rodd]

2 minutes ago, toxic said:

lovely image Rodd and the HA version 

Thanks Chris.  I guess one can never truly be done with a target like this.   But I am calling it quits till I image it again.

Rodd

[Rodd]

I hate to do it but I think it merits an inclusion....I have improved the image in several ways.  I have worked on the stars, the details in the spiral arms, and the core.  I think this is it.  2 versions--In the last version I pushed the core a bit far perhaps--I am torn--the details are sharper on Number 2 

 

[Rodd]

On ‎19‎/‎07‎/‎2018 at 03:09, ollypenrice said:

Great job on the core, Rodd. I wouldn't go too far in pushing the colour though. I don't think this galaxy is a blaze of colour, really, and I feel I pushed my own version too far. However, I did get a similar red-blue distribution.

Olly

Edit: thre is also a very faint and highly extended outer glow which, with CCD, I found needed 30 min subs to pull out. Not sure how you'd go after this with CMOS.

Olly--I have attempted to bring forth the faint outer glow.  I think this I about all the data has.  Do you think luminance is the key to the  extended glow, and if so, is there much more to be had than this?  Thanks

Rodd