Step-by-step processing workflow: the Eyes - Forums

Topic starter

Jun 20, 2025

A friend suggested that I would write a blog post describing how I processed my latest image, The Eyes (https://app.astrobin.com/i/70wutf). At first I was hesitant because I didn’t want my writeup to come across as if I knew what the “right” way to process an image is. But eventually I thought that I could just describe what worked for me, and why I thought it would when I took some of the processing decisions.

The writeup is published at https://maketronica.wordpress.com/2025/06/08/the-eyes/. I will be very grateful for any feedback or questions. On the workflow matter, of course, but maybe even more importantly on the idea of documenting the processing in this way: whether it’s useful, complete or lacking, easy or hard to follow, how to improve it.

Thanks!
Francesco

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Benjamin Moritz

Jun 21, 2025

This is great!

AstroDivers

Jun 21, 2025

Very interesting flow for the stars.
I will surely try it on my newtonian images.

Francesco Meschia

Topic starter

Jun 21, 2025

AstroDivers:
Very interesting flow for the stars.
I will surely try it on my newtonian images.

Thanks! It may not be necessary for a newtonian, but I’d still be very interested in reading about your results.

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Matt H

Jun 23, 2025

Hi Francesco,

I used your workflow to process my image of M82--thanks for publishing your writeup!

I had already spent a good chunk of time processing and reprocessing this data without being happy with the result. I was struggling with getting acceptable detail in the core and the Ha data without blowing everything out. I tried your workflow and I think it came out better than anything else I've tried yet.

I've never seen your idea of balancing the star profiles in each colour channel using Dynamic PSF and BXT. I didn't use this approach this time, but I'll definitely give it a shot on my next image.

Cheers!

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Francesco Meschia

Topic starter

Jun 23, 2025

Very nice M82, Matt!
I'm glad if my workflow helped you. You may want to try with a bit of Local Histogram Equalization, it should make the M82 filaments more visible. For my image of the Eyes I didn't need to use it, but no two images are the same…
You probably won't need to balance the star profiles with your RC reflector, as it's mostly useful to correct for residual chromatic aberrations.
Francesco

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mackiedlm

Jun 25, 2025

Thanks for this Francesco. I found it really interesting, useful and essy to follow. The method of balancing the stars is something I will use at some point. Overall a very elegant workflow and a beautiful final image. I, for one, would be very happy to see more rightups like this.

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Francesco Meschia

Topic starter

Jun 25, 2025

I'm glad! It was an experiment: preparing the writeup takes significant time, so it's good to know whether it's useful or not.

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Gordon Pegue

Jun 25, 2025

Francesco –

Thank you so much for the write up! I think it will be hugely beneficial to me since I'm a newbie PI user just learning his way. I do wish more skilled PI users would make the effort to document their process as you have done.

I would suspect that most of your workflow process would apply equally well to star clusters and globulars, would you agree with that thought of mine?

And oh, by the way, that's a gorgeous result! Well done sir.

At 640x in my 20" dob on a very transparent and steady night, I can visually pick out the subtle disk warpage in the larger pair member (NGC 4438). Of course, visually, there's no color…

Best

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Francesco Meschia

Topic starter

Jun 26, 2025

Thank you, Gordon!

The basics of the workflow are the same for all deep-sky targets, but a big part of being "experienced" with processing consists in being able to "visualize" what one would like to highlight or communicate with an image, and what steps are necessary to get there, in addition to a generic/general workflow.

For instance: for an open star cluster with limited nebulosity like, say, the Owl cluster, I may want to focus even more attention on the star colors (maybe to the point of reducing the sub exposure time during acquisition, or combining short exposures with longer one) and ignore the steps that would normally help bring out nebulosity. Conversely, when imaging a nebula immersed in a very dense starfield (the Wizard comes to mind), I would use StarXTerminator early in the workflow, before stretching, so that I can stretch the starless version, where the nebula is, more aggressively than the stars. Or, for a galaxy field with many background galaxies, I would carefully prepare a mask to make sure that smaller galaxies are not removed from the starless image even if the neural network mistakes them for stars.

Hopefully I'll find the time to write more and describe some of these cases. But I want to emphasize again: what made a difference for me is understanding why a certain operation is done rather than just knowing it's a part of a standard workflow.

Francesco

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Gordon Pegue

Jun 26, 2025

Understanding why and when a certain operation is needed is my biggest learning challenge. Also, having knowledge of what to expect when an operation is done.

Again, my thanks!

I look forward to seeing more of your work (and detailed knowledge capsules).

Gordon

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