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About GreatAttractor

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  1. Unfortunately, the reference point alignment phase is not yet as robust as I'd like (though usually works fine for my Hα material). In general, changing some of these processing settings may help: search radius: try 5-10 structure threshold: try higher values brightness threshold: try higher values structure scale: try 2-3 I have a few ideas for improving this, so stay tuned.
  2. Hello everyone, I've added a description of algorithms used by Stackistry/libskry (an open-source cross-platform stacker): link to PDF
  3. Ouch! That's what I used to do (even with 200-frame time lapses). Got quite "fast" at it, say, 7-8 seconds per image… So eventually I wrote ImPPG for: - quick batch-processing of multiple stacks - automatic alignment of sequences with sub-pixel precision Download and tutorial links available at https://greatattractor.github.io/imppg/ Exporting the animation can be also done in GIMP: - open all aligned frames via File/Open as layers - crop/resize everything to taste - preview with Filters/Animation/Playback - make a GIF via File/Export As..., choose GIF, mark "As animation"
  4. I had a Nikon D40 for a few years and loved it for regular photography (eventually replaced it with a more convenient Micro-4/3 Olympus). As for astrophotographic use, I did my first experiments with it (before transitioning to a modded webcam and then a planetary CCD). For simple Milky Way stacking and Solar System single-frame or a few-frame stacks it did the job:
  5. I also got some nice results (for the aperture), with a PGR Chameleon 3 mono camera (ICX445) and a 1.6x Barlow:
  6. I suspect the alignment mechanism is "latching" onto the sharp transition from the black background to the white border. Try cropping the images first like here:
  7. Author here; in ImPPG use the Tools/Align image sequence… menu option. Let me know if you have questions. Personally I create animated GIFs in GIMP: File/Open as Layers…, then you can crop/edit them all or individually, preview the animation with Filters/Animation/Playback…, and finally create the GIF with File/Export, choose GIF and select As animation.
  8. Main page: http://greatattractor.github.io/imppg/ Download from: https://github.com/GreatAttractor/imppg/releases/tag/v0.5.4 As requested by one of the users, ImPPG now has: New features Configurable look of the tone curve editor Enhancements Last loaded settings file name shown in toolbar All colors of the tone curve editor can be changed (from the Settings|Tone curve editor... menu, or via the conf button in the tone curve window). The System defaults mode is useful when you e.g. set a dark theme in your desktop environment - ImPPG will respect it:
  9. Unfortunately not, the eyepiece's image plane and camera's sensor are most likely at different positions. In order to use the laptop outdoors you can put it in a box: https://www.cloudynights.com/topic/523109-computer-screens-during-the-day/?p=6976454
  10. Second that. I use a CSB EVX 40 Ah AGM battery, enough for an at least 8-hour session with HEQ5 tracking and lunar/solar/planetary recording (though I don't have dew heaters). HEQ5 is hooked directly to 12 V DC, for the laptop I have a cheap 150 W DC-AC converter.
  11. GONG is also useful. It can show a time lapse of the past few hours' activity, so you'll know if something new is happening and it's time to move the scope.
  12. Very good result. What telescope did you use?
  13. I've played with raytracing (i.e. geometrical/ray optics only) a bit, indeed it's straightforward. Building a full-fledged optics simulation tool with nice 3D GUI would take a lot of time, though. Still, a simple command-line prog accepting a textual description of optics is enough for some simple experiments (e.g. define point light sources spaced on a grid, “image” them through an overly short-f.r. Cassegrain and make a time lapse out of it around the focal plane, illustrating the distortion and field curvature). Ping me if you decide to go down this route and have trouble with deriving formulas for reflection off paraboloid or hyperboloid... ??
  14. Everything shot with 90 mm refractor + Lunt 50 etalon. Smoky prominences (~1 h total): M5.3-class flare on 4/02 (0:46 h total): AR 2661 on fast-forward (5 hours with 5-minute intervals), with a minor C2.1-class flare. Solar rotation clearly visible: 7-pane mosaic:
  15. It's a “mod” which increases the aperture (and resolution) at the cost of reduced sweet-spot size (i.e. whole disk cannot be viewed in Hα). Details: https://solarchatforum.com/viewtopic.php?f=9&t=19238
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