Flats that don't re...
 
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2026-10-09 APP 2.0.0-beta48 has been released !

This is mainly a bug fix release for the reported bugs in beta47. In addition it has a significant User Interface performance improvement noticable when you need to process 1000s of images in APP.

2026-10-03 APP 2.0.0-beta47 has been released !

This is a very big release... many code optimizations/rewrites, many parts of APP are much faster and more precise, especially star analysis and registration are much faster ! Big mosaics will go much faster 🙂

And we introduce a new preview filter, which includes the new Adaptive Deep Sky Stretch and a General Levels Stretch, this has been long over due. The old preview filter (the panel on the right side to stretch and preview your data) has not been updated for a couple of years and it is a critical part of any APP session.

Adaptive Deep Sky Stretch or ADSS is a much more intuitive stretch algorithm. It is also color preserving (which is a great new addition in itself ! ) which means that the highlights are no longer bleached, color is maintained from the linear data while stretching. You can simply stretch your data using the sky background level and signal width sliders which work much easier and more intuitive. You no longer need to fiddle with the old complicated sliders with zoom buttons. All the zoom buttons for the sliders are made redundant. And you can enter slider values in the slider value fields yourself. I will make a youtube video in the coming days to explain and fully introduce ADSS. Once the video is ready, it will be highlighted on the forum.

RGB Combine upgrade !. The RGB Combine Tool has been rewritten mostly. The tool is faster and easier to use and most importantly, the Luminance slider to inject a luminance channel or channels into the RGB composite is now working correctly. It no longer bleaches the RGB colors. Combined with the new ADSS preview, you will get much better and easier great composites with great color! I will also explain this in a new youtube video.

Flats that don't remove artifacts?

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(@jerryg7)
Brown Dwarf
Joined: 6 years ago
Posts: 3
Topic starter  

Hello folks,

Tonight I stacked a couple hundred shots of Markarain's chain taken a couple days ago (30sec images, ISO400, in bortle 8 skies, no filters).  I have a Stellarvue 102mm telescope, stellarvue field flattener made for this telescope, and I'm using an Ha modified Canon 60D DSLR for the imaging.  I am having trouble understanding why the highlighted artifacts don't calibrate out with my flats?  I can actually see this artifact in the master flat but for some reason this shows up on this (and other stacked pictures of other targets.)  For some reason this one does not get removed in the calibration/registration process and I'm not sure why.  Any ideas?  I am also attaching a link to the stacked image and calibration files if that helps (in dropbox given their sizes). 

Dropbox Logo Dropbox File (Private or Invalid)

Thanks in advance for any insight you could provide.  I do see other artifacts that seem to be removed but some do not.  Is this perhaps an internal reflection and not a dust mote...does it matter?

Screenshot 2021 05 10 200726

 



   
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(@Anonymous 174)
Joined: 9 years ago
Posts: 5702
 

Hi Jerry,

Do you also use proper calibration frames to calibrate the flats etc? Thanks for the link, I'll have a look today.



   
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(@jerryg7)
Brown Dwarf
Joined: 6 years ago
Posts: 3
Topic starter  

@vincent-mod  Yes sir, I use a Master Bias frame I'd taken from some shots perhaps a few weeks ago and I use dark frames each night along with flats shot at the end of the session.  I'd included the 3 masters in dropbox.  



   
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