[RCC] Honest Critique of my M51 Image

5 replies462 views
RamonNL avatar
Hi there! I've doing astrophotography quite some time, and the processing gives me headaches. Once you get your head around Pixinsight, a new update is released (mars database for instance) and your whole workflow needs to be altered and you need to figure where it all fits in. 

Anyhow; I'd appreciate some feedback on my M51 Whirlpool Galaxy - AstroBin 

The workflow as WBPP for two stacks, LPro, and L-Ultimate to get the Ha in the core. 

I've been scratching my head on how to process these as I normally use only the NB filter to image nebula, but this was my most recent broadband target. So I've used the blurX and the NoiseX, and the multiscale gradient correction. I've removed the stars, and did a stretch on the LPro as is. The LUltimate was basically more the same, and normally I'd split the channels and process each of these, and stack them together, yet here I removed the stars, did a stretch on the LUltimate stack, added LUltimate and LPro via Pixelmath with a trial and error ratio between these two, and added the stretched the color saturated LPro stars. 

I'd like to make the red more pop, but that is more a trial and error for me, and I always struggle with the stars / object, I try not to overdo the stars (make the object more visible) but that is a tight balance. I'd appreciate any feedback you might have.
John Stone avatar
purple background?  or is my monitor calibration off?
RamonNL avatar
John Stone:
purple background?  or is my monitor calibration off?

I've made worse to put it mildly, but there is indeed a slight purple background.
John Stone avatar
Maybe try a little background neutralization?  (be sure to set the limits to match your actual background levels)
Oscar H. avatar
background neutralization will not remove those dark blue/purple spots

maybe try MGC (with a smaller gradient scale), followed by SPCC, or background neutralization if you don't want to start in the linear phase again (because SPCC requires linear data, if I remember right)
Oscar H. avatar
sorry double post
Related discussions
The Witch watching Rigel - suggestions?
I am not happy with this result and I think I know why, but could use any criticism. https://www.astrobin.com/0zrmfg/ This is the Witch's Head and includes Rigel. Most of it was shot from a Bortle 7 location, and the resulting stacks had very, ve...
Jan 22, 2023
Both posts show astrophotographers seeking feedback and critique on their deep sky object images while discussing technical challenges they encountered during the imaging or processing workflow.
Flats in remote imaging
Hello - I am exploring what it would take to set up an extra scope/mount I have for remote imaging, and specifically looking at flat generation. I'd like my flat frames for all filters to be 4s or longer. I have the following questions: How many ...
Aug 7, 2025
Both posts discuss technical aspects of astrophotography workflows and equipment setup for capturing deep-sky images.
Mounting telescopes permanently on motorhome for easier astrophotography setup
Greetings all, I’m an avid “traveler” that drives around 1 hour to access the best sky in my country for all my sessions (bortle 4). The way that I managed to do that is to store all of my astrophotography equipment permanently in my car’s trunk with...
6 days ago
Both posts discuss the practical challenges and workflows involved in astrophotography, with one focusing on image processing difficulties and the other on equipment transportation logistics.
Flats
GDay all I have a creek running behind my place and hence lots of trees. I image between them and on my deck. Some nights I can only get ten subs if Im lucky and anything quite high no dramas getting a decent amount. Many times Im lucky for ten. In t...
Nov 15, 2025
Both posts discuss the practical challenges astrophotographers face when trying to capture deep-sky images from less-than-ideal conditions.
Scientific processing or artistic processing, which one is more important for astrophotography?
Whether a scientific or artistic approach is better for processing our data is always a debating topic in the astrophotography field. One could say: An image processed with more consideration for preserving original authenticity is scientific; others...
23 days ago
Both posts discuss the challenges and approaches involved in astrophotography image processing workflows.