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.
Hi, when using the ZWO 183MC Pro I'm having problems with calibrating out the amp glow. I have the "adaptive pedestal/reduce amp glow" checked of course, but that doesn't fix the problem. It did help with more dark frames. I also realized that the offset value of my darks and lights were different so I made new and more darks. Now the darks have the same temperature, exposure and offset as the lights. Still there is noticeable amp glow in the stacked image. I've also tried a few different settings when stacking, but nothing seems to make much difference. What am I doing wrong?
I forgot to mention that the darks and lights also have the same gain of course.
I used to image with a 183. Make sure the adaptive pedestal, scale masterDark, and scale MasterDarkFlat is off and don't use Bias frames. Shoot Dark Flats which are darks taken with the same exposure time as the flats. Bias frames never worked with my 183.
I don't use dark flats, and I wouldn't have thought that bias frames could be a problem so thanks for the advice. I will test this as soon as we have clear skies. Thanks!
I have two ASI183MC-Pro, and I am using this sensor for three years now. Never had this problem. I use Dark/Flat/BIAS ever since.
The BIAS and the Darkframes must have same Gain, same temperature, same offset. The Darks also must have the same exposure time as your lights.
The lights do not have to be at the same settings, they only represent the optical imperfections and can be taken at a lower Gain if you for example have problems regulating your flatpanel down to low brightness.
Interesting, and good to hear that there is a way around this problem. What I do different is that I don't use flats so I'm going to try that first. My I ask what settings you are using in APP?
@t-boevaonline-no Always standard-settings for this sensor.
Flats won't correct sensor-related stuff like ampglow. Flats only correct weakpoints of your optical train (vignetting, dust, ...)
Ampglow is corrected by darkframes, so these should be taken with care.
I've made sure that my lights and darks have exactly the same exposure, temperature, gain and offset, but there is still amp glow in the final stack. I took 84 lights and 60 darks, and thought that would be enough darks, but maybe it isn't?
I do not have a ZWO 183MCP; but I do have a ZWO 294MCP with significant amp glow. One thing that seems to help to remove the amp glow (and generally give better calibration results) is to use different darks for the lights correction than the bad pixel map. That is, prepare a BPM first and load it as a master. APP will then not use the light calibration darks to create a new BPM. For the BPM you can use long exposure (like 60 to 300 sec) room temperature darks. Correctly prepared the BPM can be good to use for a year or so.
BPM only corrects bad pixels, not ampglow.
@jhart Well, I have both these cameras:-) I would say that the amp glow is even worse with the 183. However, I have not tried the technique you are describing so I will give that a try. Thank you!
A little bit late to this discussion but, after a long period of not using my ASI183 camera, I recently picked it up for a particular project and noticed very pronounced amp glow, despite all new master calibration frames. I never used to have a problem calibrating this out and so I suspect that some changes in the APP algorithms may be at play here.
Not sure what the actual cause is but I suspect, as noted in previous responses, something to do with the way that bias frames are handled (maybe bias is being subtracted twice in producing masters then using them to calibrate?). The resolution was straightforward for me - I simply omitted the master bias and just used master dark and flats. Amp glow disappeared.
This is very reproducible (for me at least) - using the same dataset, add bias into the mix and (very bad) amp glow re-appears, leave bias frames out and no amp glow. Odd.
That is strange. I am currently using two ASI183MC-Pro, one is three years old, the second is new. No problems in the past or now with BIAS and ampglow.
You should make your BIAS frames with the shortest available exposure time. 1ms usually. Watch out for light-leaks.
Interesting to hear that you never had a problem with amp glow until now. If anyone watches "Cuiv the lazy geek" on Youtube his was very specific about not using bias frames with the 183 in one of his videos. The same supposedly applies for the 294 camera.
I was beginning to believe that there was something wrong with my 183, but your experience suggests otherwise. So far I have had no luck with calibrating out the amp glow completely despite making flats and dark flats. However, these file were made afterwards and I cannot guarantee that the camera was in the exact same position as when I took the lights, and the same goes for the focuser. So I am patiently waiting for a clear night to take new lights with new flats and dark flats. Hopefully this will work.
@t-boevaonline-no BIAS-Frames are not related with ampglow, only the darkframes are. Because at 1ms exposure the sensor can not catch any ampglow.
Camera-position is only relevant for flatframes+lightframes as the optical path is closed and has no influence on BIAS/darks.
But one thing I noticed while using different controllers (ASIAIR, NINA, Stellarmate): Only use calibration-frames you made with the same controller. I do not know exactly why, but I had massive trouble when using calibrationframes from the ASIAIR with lightframes shot with NINA. Never do that, even if you exactly know your offset, there always is some difference that is significant.
I didn't know that so I will keep that in mind. Throughout the whole process I've been using the same controller. That is the ASIAIR in my case.
I don't think I've mention this earlier, but I tried to stack the same data with ASIDeepstack and got zero amp glow. This suggest again that there is something going on with APP in my opinion.
