GreatAttractor

I got my GSO RC8 mainly for solar work, but it's promising also for planets. I had a spell of good seeing yesterday: 23 minutes, 3-minute intervals, PGR Chameleon 3 mono (ICX445) + Baader Red 610 nm long-pass filter, f/16, resized to 150%, AviStack 2 + ImPPG. It seems I have to tweak the collimation some more (the "limb rind" artifact should be symmetric, and not more prominent lower in the image). The small bulge in the upper right is Olympus Mons.

Excellent animation. At this scale I'd suggest shorter intervals for smoother motion. E.g., I used 30 seconds here (15-second videos with 15-second breaks):

Indeed. One gets better at it with time, I got down to maybe 3-5 s per image (using transparent layers in GIMP); but still, those 200-frame time lapses were tiring. So I wrote a tool to automate it, give it a try: ImPPG TL;DR version: download the program, choose Tools/Align image sequence... from the menu and enjoy the frames aligned with sub-pixel precision. The batch processing function may be also of interest; check the tutorials linked on the homepage.

Great job! Did you align the frames manually?

And me, in Firefox and Chrome. Could you upload as an animated GIF?

This sounds like color-reduction side effects (GIF uses lossless compression, so compression artifacts like in e.g. JPG are in fact not possible). Make sure to select Image/Mode/Grayscale before exporting.

Right, you cannot save the layers individually with one command. In my workflow, though, it's not needed: I "open as layers" to load all frames, crop and/or resize, check the animation using Filters/Animation/Playback..., and then export straight to an animated GIF.

Excellent! To me it's the best thing to image on the Sun: a boiling, spiking active region right on the limb. Good to know it can look spectacular also in CaK. Don't forget to try the mass cropping of your frames in GIMP.

Good to know about the required cadence for CaK time lapses. I've been very satisfied with my older Chameleon3 (up to 30 fps at full frame, perfectly fine for Hα and WL), but now I'm reconsidering getting a newer, faster CMOS model.

Based on these newer images I agree, all the lines are really coming from underlying data. As you wrote, they should not be oversharpened (then they look unreal, too thin and too uniform in brightness for the aperture used). And the animation rocks! (I like the "one pass" version better.)

No, the bright "celullar" pattern of lines is there for real. It's just that it gets "overcooked" when you keep applying deconvolution over and over. E.g., those super-fine bright lines in your 7th pass don't look like something that could come out of 127 mm aperture with the kind of PSF it has - but rather like accumulated ringing artifacts. (Note how in Valery's and DOT images the lines are randomly oriented, but the 7th pass shows them mostly near-vertical and near-horizontal.) Of course, I can't be sure where exactly "overcooking" begins - one would have to, I guess, capture at the same time and conditions also with a large aperture and compare the results.

I have no experience with CaK imaging and processing yet, but your 4th pass and above definitely look "overcooked" (with "ringing" artifacts of sharpening). It's a good idea to compare to DOT images (maybe also the 1-meter Swedish Solar Telescope has some CaK material in its gallery). Another thing you could try is running the raw video through Stackistry and checking the mosaic of best fragments it generates. (In case of white light material, it would nicely show granulation in the whole FOV.) This gives some idea about how the "real image" would look without seeing effects (though it will be noisy and low-contrast, so a histogram stretch will be needed - can be done in ImPPG, just disable all sharpening and use the "stretch" button in the curve window). (See the tutorial on how to get this best fragment mosaic; make sure to enable subtitles. You don't need to wait for stacking to finish, the mosaic is available as soon as "Quality Estimation" finishes.)

Thanks to Rusłan there are now Russian and Ukrainian translations: Version 0.6.2 can be downloaded from: https://github.com/G.../imppg/releases

Hi David, Stackistry is not a mature tool yet, though it usually works fine for solar Hα material (that's how I use it). Another open-source stacker has been recently announced, could be of interest: PlanetarySystemStacker.

Don't worry, it's not that fragile. I recommend one of those optics cleaning microfibre cloths - sweep the sensor (or the window glass if your camera has one) with minimal pressure (since we just want to catch the specks, not "scrape away a stain") a few times, that should do it. Also, when changing cameras / attaching C-mount lenses etc., minimize the time the sensor is exposed - have a cover ready and reattach it immediately.