19 June 2021: Our upload server https://upload.astropixelprocessor.com/ has been migrated successfully to our new office with higher upload and download speeds (nearly 10MByte/sec up/down ) ! We now have 1 general upload user called: upload with password: upload. The users upload1 - upload5 have been disabled.
31 May 2021: APP 1.083-beta2 has been released ! APP 1.083 stable will follow soon afterwards. It includes a completely new Star Reducer Tool, New File Saver Module, Improved Comet registration and much more, check the release notes here!
Very pleased with Star Reducer Tool
I am currently working on Sh2-86. Star size reduction tool is working great, even on my clunky old Celeron processor, but it helps that my sensor is only 1392x1038.
Even if I don't want to remove all stars, I begin by checking the "Remove Stars" checkbox. That disables all sliders except "Star Radius". I play with that one until I find the desired result. Then I uncheck it and play with the "Star Size" slider. I don't usually touch the other sliders.
In the first attachment, I have 5 hours invested with a 7nm Ha filter. Scope is a 71mm f/5.9 refractor. In the last attachment, I used APP to mix in 2 hours of RGB that I just started to capture. More to go, but you can see that the star colors are nice. So far the nebula is dominated by luminance (Ha) but that should change as I capture more color
In this image the color is more true to life. I injected a small amount of the RGB data into the Luminance channel instead of relying completely on Ha for Luminance. This made the red "pop".
That's a very nice iteration process you're using, seems to work nicely! I think the updated version will help to get even better results, but very nice! And thanks for the nice comments.
Thank you, Vincent.
I changed strategies. In my previous attempts, I loaded Ha into Luminance, and relied on the RGB stacks to supply the nebula's color. In theory it should work, but it requires LOTS of integration time in RGB. Now I load Ha to Red, which if you think about it makes a lot of sense. However, the problem is star colors. Proper star colors are in the RGB stacks. If I were to simply combine the Ha with the RGB, then there would be an over-abundance of red which skews star colors. The solution is to remove the stars from the Ha stack. Thankfully, I can achieve that with APP 1.083-beta2.
Next step is to combine the nebula and the stars. I used Affinity Photo. (I should look to see if APP can do it, but Affinity seemed to be the intuitive choice.) Affinity has a tool available from the File menu called "New Stack..." (not to be confused with "New Astrophotography Stack...") Afterwards, I cropped it, denoised it, and adjusted shadows and highlights.) That was it!
In this final version, I pushed the contrast to show the luminance variations in the nebula, however, I could only achieve that by applying star reduction to the RGB stack. I reduced them to 40% of their size. There are some artifacts around the stars when you zoom in, but I am very pleased with this result. The proper thing to do is to recapture RGB with a shorter exposure to reduce star saturation.