TECH QUESTION FOR SOLAR PHOTOGRAPHY EXPERTS
When I photograph the Sun, whenever I process in imPPG, to get any kind of clear prominence, end up also getting my limb processing too dark (or too bright, when I invert), without natural smooth transition across the limb.
How do I avoid this? Please explain, and if you have screenshots of imPPG curves, that would help.
Thank you!
I am not a solar expert but my guess from what little I know, is that the longer exposure to needed for the prominences also picks up the fainter part of limp, slightly extending it outward. I see this in a lot of solar Ha images and I suspect it has something to do with how narrow the filter band is. No idea what the processing fix is. I’m hoping the solar guys here will jump in on this thread.
Its been a while since I used ImPPG for solar (the astrobin user GreatAttractor should be the best person to answer that I suspect).
But if you have PI, you can also try the Solar Toolbox that Bill Blanshan and Mike Cranfield have put together. There if you choose the setting for solar limb, that controls the way the limb edge ends up being processed.
Thank you
The astrobin user GreatAttractor is the guy who makes the program. I’m not going to bug him with that. I’ve already asked him for feature requests (that he says he may implement.)
I have SolarToolbox too, I use it only for orange coloring with one click. When I do processing with it, the Sun always seems “overbaked.” I guess I should work with the settings more than the little I have.
But I know this is an issue with imPPG settings, I just don’t know what to change. I think imPPG is the way to approach it, since it’s the classic main program used for this.
Good reply though.