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.
When I finish my images, I found that my background looks terrible, how can I fix this to make my background smoother or better?
And how to create a "Luminance" file with my RGB images?
Thank you!
@alexlee24 Hi,
It is hard to say what caused this without more info. What camera did you use? What calibration files? Exposure time, gain/offset/iso, temperature? Please try to give us as much information as possible.
Thanks, Wouter
@wvreeven I use Canon90d with VixenED102ss, the images were 120sec*100 iso1600 with dither, and I have dark bias flat and dark flat, the environment temperature is about 25C and have 95% humidity with Bortle scale 5~6.
Thank you.
@alexlee24 Thank you for the additional info. How much do you dither? For APP to work well, you need to dither at least 15 or even 20 pixels in the imaging train. Since all imaging software let you set the dither offset in the guide train, you need to compute the corresponding offset in the imaging train using the plate scales of both trains to make sure that you have a sufficiently high dither offset.
The image that you posted, is that the integration result? In what way don't you like the background? Too dark? Too noisy? Something else?
@wvreeven Ahh...I only set 5pixel (RA only) per image for dither.
Yes, this image is after integration and tools. I think my background looks not "average" like some pixel is brighter than other pixels, it makes my background looks like a lot of grey squares. It's obvious at my bottom left. Maybe too much noise? or decrease too much noise in HSL to make this too evident?
Thank you.
@alexlee24 Can you post the image as is after integration without applying any tools? Just load the image in the image viewer in APP and then take a screenshot.
Thanks.
@alexlee24 I think the background looks like it is expected when using an uncooled camera. More dithering will help but there always will be chromatic noise in the background. Using a cooled camera combined with proper dithering will suppress that a lot more.
@wvreeven Thank you. How many pixels per image for dither do you suggest for DSLR? No budget for a cooled camera right now 😥 .
Thank you. Cheers.
@alexlee24 I don't think there is a difference in dither settings for cooled and uncooled cameras. I'd say go for 20 pixels and see if that helps. Don't expect miracles though. Noise from uncooled cameras is notoriously hard to beat.
