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.
Is there a tutorial for OSC processing in APP? All I can find is OSC along with Narrow band etc. but none for simple OSC integration and processing.
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Thank you
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Jas
Most steps for OSC are the same as in the combined tutorial. You can basically leave all settings to default for regular OSC processing. Things you may want to switch on are LNC and MBB in tab 6, also just use their defaults.
Basically you load in your OSC data as lights, add the calibration data and go to tab 6 and click integrate. That should give you a nice result already.
When I try to create master flats, I get really bizarre results with OSC. Would I be better off just adding in the sub flat frames to the lights I am processing and let APP create the master flat that way? There is very little guidance as to processing OSC.
@wvreeven Thank you, but, and not to be argumentative, only curious, why can't the APP just create Master Flats from flat subs without Lights data? This was troubling even when I was shooting RGB. I always was reverting to Nebulosity to make my calibration frames to then use in APP.Â
@applal What version of APP are you using? APP has been able to create master flats without lights for many versions now. Just load the raw flat frames and either raw dark flat frames or a master dark flat created by APP, go to tab 2 and click "create Masters & assign to Lights". Note that, as always, if the exposure time of the dark flats is not the same as the lights, you'll need either raw bias frames or a master bias. The text on the button may seem to suggest that Lights are needed but this is not the case.
1.083.2 (1.083.2) -Â
I just attempted exactly what you described. Just with flat calibration files.
It came out as green, with 3 different intensities, as distinct "panels" Â from top to bottom. Â
I had NO other files, just the flat frames. And looked at individually, they looked like one would expect. I would like to know, on the very first panel that opens when adding the Flats to the Flat button, it asks "To Which Filter..... assign..." Do I select RGB, All Channels? do I deselect everything? There is no hint to guide one to the knowing in the case of just making masters.Â
When I go to do as you described, "Create masters and assign to lights" I get the Critical warning error, and just ignore it.
I just ran it with All Channels, and this is the result. My concern is not so much the green, as much as the sharp horizontal line near the middle. I have attached a screen shot for you to see. And could you comment on the question of what to select, and should the Master Flat be green?
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@applal As I wrote in my previous comment, dark flats are required in APP to create a proper master flat. Since you wrote that you only processed flats, the result isn't what it is supposed to be and you get the critical warning popup. Please try again with dark flats and verify that that solves your issue.
Regarding the question what channel to apply, APP should offer to apply the "FILTER" tag at the bottom of the popup and that is enough for your flats since APP detects that they are RGB images. As soon as your flats have loaded in APP you can verify that by looking at the entries in the file list at the bottom of the APP window. There APP will indicate that it has loaded the flats as RGB flats:
Alan, just to give confidence,
i also have osc asi071mc.
do a flat dark, same exposure, gain, temp as flat.
Also note: in default viewer, if you do not click neutralise background when looking at a raw file from a rggb colour chip, you will see a green file, as two green pixels to each of one blue and red.
I am sure you know this, and you are just commenting on the band, but just for info.
Personally, i have a master flat i create with just the flat and flatdark files and use it until i change anything in the imaging train. No need for the lights in creating.
works out of the box for me.
Thanks to both Andy, and Wouter-Moderator for your simple to understand guidance.
While it was not as intuitive as I expected, it is fine and certainly works! And I also found what caused that strange horizontal line in the image I uploaded to this thread. It turned out, that, for reasons unknown, I had a few flats subframes that were only half illuminated. Once I deleted them from the processing, THAT problem was gone. APP and I are once again getting along just fine.Â

