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.
I have some data from ZWO294MC Pro camera used with L/H/S/O filters. Each filter's files were processed with darks, bias and flat frames.
This is a colour camera, so I'm using OIII/Ha/SII debayering algorithms.
For Ha and SII as well as for L filter, the amp glow is 95-99% eliminated by the dark frames, but for OIII the amp glow is horrendous.
Either darks are not applied to OIII algorithm or it's amplifying the amp glow somehow, or I'm missing something.
@mseningmail-com Can you tell a bit more about the lights and the darks? What exposure time did you use for them? And just to be on the safe side, can you confirm that they were all taken at the same temperature, gain and offset? What software did you use to take them?
I originally shot the dark frames on the same night as I took the lights back in October in the local mountains. The camera was cooled to -10C, in case I needed to re-shoot darks later: -20C would not be achievable from my home because it gets hot here most of the year.
All exposures were at Bin1, G=200, Temp=-10C and Exp=120s. AFAIK the offset is built into the camera and FITS header says it's always 30.
I had to reshoot darks several times until I got reasonable results in most filters. But OIII is the worst.
They were taken with ZWO ASIAIR and ZWO ASI294MC Pro.
The latest Dark FITS header:
SIMPLE = T / file does conform to FITS standard
BITPIX = 16 / number of bits per data pixel
NAXIS = 2 / number of data axes
NAXIS1 = 4144 / length of data axis 1
NAXIS2 = 2822 / length of data axis 2
EXTEND = T / FITS dataset may contain extensions
COMMENT FITS (Flexible Image Transport System) format is defined in 'Astronomy
COMMENT and Astrophysics', volume 376, page 359; bibcode: 2001A&A...376..359H
BZERO = 32768 / offset data range to that of unsigned short
BSCALE = 1 / default scaling factor
CREATOR = 'ZWO ASIAIR' / Capture software
OFFSET = 30 / camera offset
XORGSUBF= 0 / Subframe X position in binned pixels
YORGSUBF= 0 / Subframe Y position in binned pixels
FOCALLEN= 247 / Focal length of telescope in mm
EGAIN = 0.398999989032745 / Electronic gain in e-/ADU
XBINNING= 1 / Camera X Bin
YBINNING= 1 / Camera Y Bin
CCDXBIN = 1 / Camera X Bin
CCDYBIN = 1 / Camera Y Bin
XPIXSZ = 4.63000011444092 / pixel size in microns (with binning)
YPIXSZ = 4.63000011444092 / pixel size in microns (with binning)
IMAGETYP= 'Dark ' / Type of image
EXPOSURE= 120. / Exposure time in seconds
EXPTIME = 120. / Exposure time in seconds
CCD-TEMP= -10. / sensor temperature in C
DATE-OBS= '2021-02-03T04:21:12.164' / Image created time
INSTRUME= 'ZWO ASI294MC Pro' / Camera model
BAYERPAT= 'RGGB ' / Bayer pattern
GAIN = 200 / Gain Value
The sample Light FITS header:
SIMPLE = T / file does conform to FITS standard
BITPIX = 16 / number of bits per data pixel
NAXIS = 2 / number of data axes
NAXIS1 = 4144 / length of data axis 1
NAXIS2 = 2822 / length of data axis 2
EXTEND = T / FITS dataset may contain extensions
COMMENT FITS (Flexible Image Transport System) format is defined in 'Astronomy
COMMENT and Astrophysics', volume 376, page 359; bibcode: 2001A&A...376..359H
BZERO = 32768 / offset data range to that of unsigned short
BSCALE = 1 / default scaling factor
CREATOR = 'ZWO ASIAIR' / Capture software
OFFSET = 30 / camera offset
XORGSUBF= 0 / Subframe X position in binned pixels
YORGSUBF= 0 / Subframe Y position in binned pixels
FOCALLEN= 247 / Focal length of telescope in mm
EGAIN = 0.398999989032745 / Electronic gain in e-/ADU
XBINNING= 1 / Camera X Bin
YBINNING= 1 / Camera Y Bin
CCDXBIN = 1 / Camera X Bin
CCDYBIN = 1 / Camera Y Bin
XPIXSZ = 4.63000011444092 / pixel size in microns (with binning)
YPIXSZ = 4.63000011444092 / pixel size in microns (with binning)
IMAGETYP= 'Light ' / Type of image
EXPOSURE= 120. / Exposure time in seconds
EXPTIME = 120. / Exposure time in seconds
CCD-TEMP= -10. / sensor temperature in C
RA = 10.943715 / Object Right Ascension in degrees
DEC = 41.3451 / Object Declination in degrees
DATE-OBS= '2020-10-19T09:21:39.154' / Image created time
FILTER = 'O ' / Filter used when taking image
INSTRUME= 'ZWO ASI294MC Pro' / Camera model
BAYERPAT= 'RGGB ' / Bayer pattern
GAIN = 200 / Gain Value
TELESCOP= 'EQMod Mount' / Telescope name
Â
...I can still see some amp glow in Ha and SII stacks, but RGB (OSC) looks relatively good - I can crop what's left.
I don't know if it's related, but I'm still on Version 1.082. I reported a bug previously where "extract Ha" and "extract OIII" algorithms were resulting in the same image and also if any drizzling were used it would leave black pixels in there. I heard it's fixed in 1.083 beta3, so please let me know if I should just wait for the new version to try stacking it again?
Just to be clear, these images were shot with ZWO ASI294MC Pro, which is an OSC camera, and for narrowband filter images I selected Ha/OIII/SII debayering algos as opposed to "Exctract ___" algos.
