Share:
Notifications
Clear all

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.

Image Banding

6 Posts
4 Users
0 Reactions
4,834 Views
(@thedwo)
Red Giant
Joined: 7 years ago
Posts: 31
Topic starter  

My recent set of images, taken with ASI294MC-Pro camera using NINA, show significant banding when processed via APP. I have over stretched these to highlight these artifacts.

Any advice as to what may be causing this is appreciated.

PelicanA
ElephantsTrunkA

 



   
ReplyQuote
(@astrogee)
Black Hole
Joined: 8 years ago
Posts: 244
 

Well I guess that's bias noise. You can calibrate out with bias frames. I have a 294 and I don't think I have much bias noise - lots of amp glow though. When I capture I have the offset set to 8, this setting was automatically selected by my capture software AstroImager (Mac product)



   
ReplyQuote
(@thedwo)
Red Giant
Joined: 7 years ago
Posts: 31
Topic starter  

Thanks for that comment I'll check it out. I have also been advised that the culprit could be USB-3 bandwidth, where too many devices are calling for access at same time.

Cannot check properly until some clear skies return - and who knows when that will be ;-((

 



   
ReplyQuote
(@astrogee)
Black Hole
Joined: 8 years ago
Posts: 244
 

I don’t know who told you that but that’s not how digital communications works. All transferred data is verified to be valid and complete. What you see is in the image you took. Bad communications would cause lost data. Not noisy data. 



   
ReplyQuote
(@mestutters)
Neutron Star
Joined: 9 years ago
Posts: 175
 

Hi Frank,

I take it that we are looking at a stacked image in your screen-shot and not a single frame?   The nebula signal looks pretty weak to me so I assume you are not integrating that many frames and/or they are of short duration?

Have you tried examining your individual subs using a hard stretch with viewer in a) linear, and b) l-calibrated mode?  When switching to the l-calibrated mode, much of the noise and other unwanted artifacts in your linear subs should be removed. If this is not the case  then I would carefully review your process for capturing and stacking your calibration frames. Also try experimenting with the Cosmetic Correction options in 2) Calibrate as this may help.  Have a look at the early part of this video tutorial:

https://www.astropixelprocessor.com/complete-lrgb-tutorial-of-ngc292-the-small-magellanic-cloud-by-christian-sasse-itelescope-net-new-version-app-1-081/

Another thing you might look at is the power supply to your camera.  Is this internal battery or a converter?   I had a problem a year or two back which I eventually tracked back to low input voltage to my camera.   If camera is unable to draw sufficient power then I think you can get strange patterns in the lights which will not calibrate out.   Do you see any differences between images taken at start of your session versus the end?

best of luck

Mike

 


This post was modified 6 years ago by mestutters

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

It would indeed be interesting to see how a single sub looks like and if you have the proper calibration data. The noise seems very high, what gain and other settings were used?



   
ReplyQuote
Share: