Astrophotography Stacking

[Anderl]

Hello,

currently I am using Affinity Photo for stacking and processing Astro images. Some days ago I took photos from Orion nebula using a Canon EOS R (not astro modified) adapted to a telescope in a little observatory. Conditions: No filters, ISO 3200, images with 5, 15 and 30 sec exposure time - and corresponding darks, bias - RAW format CR3.
I stacked the images as recommended in the tutorials (each exposure time separately). I used the standard conditions for stacking and RAW options as recommended with WB camera.
With increasing exposure time the stacked images became more and more flat and somehow overexposed, very bright. For further processing I tried the macro for tone streching etc.
as recommend but the result is very strange. Completely overexposed, strange colours etc. The recommended procedure cannot be used as expected. It works much more better if I 
uncheck ICC management and uncheck the layers curve and tonal correction. In this case Í am able to use the macros recommended.
So I have no idea what is the suitable procedure of image processing under the conditions described. What is the effect of ICC, what does it mean, what happens in the background?
In case I uncheck ICC or I reduce Gamma correction it always results in a darker background, not in a flat and overexposed image.
What can I do to be able to process my images correctly leading to more satisfaction while using Affinity Photo? The corresponding tutorial from James Ritson is very good
in terms of explanation and handling. But following these instructions it will not lead to the result as demonstrated in the video.
I need your help! What can I do for more understanding of the complex interactions behind?

Thank you very much for a feedback!
Best regards, take care

Andreas

 
 

[Dan C]

Hi @Anderl,

Welcome to the Affinity Forums

My sincerest apologies for the delayed response here!

Can you please provide a link to the tutorial you're referring to, and a screenshot of the resulting image within Affinity Photo?

How many files are you importing into each category of frames?

Unfortunately I'm not personally overly familiar with astro-stacking, however If you can provide these files in a link, then hopefully other Affinity users with more Astrophotography experience may be able to provide further recommendations!

[Andreas Sauer]

Hello Dan,

thank you for your answer. I will give some additional informations to describe the problem observed. 
You will find all tutorials in Affinity Photo under "Help", "Tutorial". The tutorial I am referring to is named: Astophotography Stacking: One shot colour processing by James Ritson. I exactly followed the processing steps in this tutorial. But as I described in my comments before I could not use all the steps and even not the macros provided with success. It resulted in somewhat strange. Maybe it is up to me but I could not figure out why. Again, what is the difference between with and without ICC management, for instance? I think more detailed explanations with respect to the usage for astrophoto processing is necessary in order to increasse the understanding of prcessing steps to be used or better not.
For my stacking procedure I used 20 images only for each exposure time (5 sec, 15 sec and 30 sec) and 15 darks and Bias each. But I stacked it separately, of course.
I linked the stacked 5 sec image and some modifications as indicated (without ICC, using different macros...).
I hope that someone can give me some more explanations about the influence and interactions for astrophoto processing with Affinity Photo.

Link
https://hidrive.ionos.com/share/0elimf95xt

Thank you in advance, take care

Andreas

 

[Dan C]

Thanks for confirming that for me and my apologies for the delayed response - unfortunately without your source images themselves I'm having a little trouble understanding the document provided.

Can you please upload a copy of your source images to the below link for me?

https://www.dropbox.com/request/NbvJfdcwM8721ogtM0ni

Once uploaded, please reply here to let me know!

On 3/10/2022 at 6:37 PM, Andreas Sauer said:

what is the difference between with and without ICC management, for instance?

Are you referring to the Display Transform options within the 32bit Preview Studio?
If so, this is covered in the 32-Bit Preview help file page -

Quote

Display Transform—allows you to switch between a non-linear view using the current display profile, linear light or an OCIO transform:
ICC Display Transform—non-linear transform using the current display profile.
Unmanaged—a linear light view where no transform is applied.

[irandar]

Hello Andreas,

I wonder if you were able to get a solution to your Affinity astro stacking problem of last year.? I have had similar problems. 

Regards, Irving

[Dan C]

Hi @irandar,

Can you please expand on the issues you are having with Astro-stacking?