M31 Andromeda - The wonders of processing

[Rossco72]

Off the bat, nothing new here. This is just a journey for me on the Pixinsight / Photoshop processing journey.

This is all the same data, just processed at different skill levels and software.

My first process of my Andromeda data was in Photoshop, stacked images from ZWO ASIStudio and aligned in photoshop. I'm not an expert in PS by any means, and I was actually pretty happy with this at the time.

After lots of cloudy nights and no new data to keep me interested, I started watching tutorials on Pixinsight and finally took the plunge! This now shows the same subs (well almost as PI rejected a few through the sub-frame selector) bt fully processed in PI with no photoshop at all!

I was even happier with this and even posted on here.

My final, if we can ever really say final  , process took on board what I have learned and practiced to date, I think this is the best of the 3 but would love to hear your thoughts. Who knows, I may go back and do this again later this year with another 6 months practice under my belt. But I would really hope I will have captured more data and better framing this year.

 

One thing for this year will be shorter subs, try not to blow out the centre too much! 

I did have some pretty bad LP gradients between the channels with a very noticeable magenta bottom left to green top right that proved stubborn to shift.

[tomato]

I think you have made significant progress across the 3 images, for me the core colour and outer arms on the RHS is spot on in image 2 but you have the strong magenta dust lanes on the LHS. You have done a great job on controlling this in image 3 but have lost the core colour somewhat.

M31 is a very popular target for obvious reasons but IMHO it is a real challenge to process the colour and get it somewhere close across the entire galaxy. Still, our constant supply of cloudy nights gives us plenty of time to have another go.

[SamAndrew]

Big improvement, I still reprocess images I took when I started 12 years ago; hang on to the data  

Final image background looks a touch green on my monitor, maybe try SCNR with an inverted luminance mask to hit the background. 

Edited April 3, 2023 by SamAndrew

[ollypenrice]

It looks like the big problem you're facing is a strong left-right colour gradient, so that needs to be your first step. I would place the DBE markers as shown below and with a high tolerance. I avoid ABE on galaxies because it tends to put markers too close to them and so create a dark ring round them.  Using too many markers is counter-productive.

The third image has the best gradient control but it is still there if we turn up the saturation. In Photoshop you can use the colour sampler tool (set to 3X3 or 5x5 average) to sample the background sky. I like the three colour channels to be equal.

Olly

[Rossco72]

5 hours ago, ollypenrice said:

It looks like the big problem you're facing is a strong left-right colour gradient, so that needs to be your first step. I would place the DBE markers as shown below and with a high tolerance. I avoid ABE on galaxies because it tends to put markers too close to them and so create a dark ring round them.  Using too many markers is counter-productive.

The third image has the best gradient control but it is still there if we turn up the saturation. In Photoshop you can use the colour sampler tool (set to 3X3 or 5x5 average) to sample the background sky. I like the three colour channels to be equal.

Olly

The joys of LRGB imaging with a mono camera over different weeks with different moon positions! (I do try to avoid LRGB when the moon is close to the target or more than 50% lit. However with so few clear nights in Scotland, we can't afford the luxury of only choosing the best nights 😂😂😂

Would you suggest DBE on each channel before combination or just wait and do it on the RGB image?

[ollypenrice]

27 minutes ago, Rossco72 said:

The joys of LRGB imaging with a mono camera over different weeks with different moon positions! (I do try to avoid LRGB when the moon is close to the target or more than 50% lit. However with so few clear nights in Scotland, we can't afford the luxury of only choosing the best nights 😂😂😂

Would you suggest DBE on each channel before combination or just wait and do it on the RGB image?

I get gradients with OSC and mono from an extremely dark site. They may actually be worse with OSC. Why? Not a clue!

Personally, I do DBE on an RGB image but I know one or two other imagers who  do it 'per channel' first. I'd give it a go. You could even try it both ways on the same data - DBE the individual channels and then the output RGB.

Olly