View Full Version here: : Yet another first effort with Helix
muletopia
09-10-2022, 02:33 PM
After months of cloud after acquiring a new to me Mewlon 250, downloading a trial version of AstroPixelprocessor and learning some basics of that program, the attached image emerged.
Comments and critique welcome
Chris
muletopia
09-10-2022, 02:35 PM
well maybe
AdamJL
10-10-2022, 11:32 AM
Hey Chris. Good start! I love the spikes from the Mewlon, they're certainly unique!
The main comment I would make is that you need to take flats. You've got dust bunnies all over the image and they can easily be removed with flat frames (but they can only be taken when you take your lights, unless your setup never moves), plus the flats will help with that vignette issue (though it seems something has over-corrected them, hence the light corners)
ChrisV
10-10-2022, 12:31 PM
+1 with Adam. Nice start and I love the JWST spikes!
Flats- all of what Adam says. It will look much better (vignetting and dust bunnies) and allow you to stretch more out of it
AstroViking
10-10-2022, 12:45 PM
For an image without flats, it's come out very well. I can't wait to see what it looks like once you get the flats sorted out.
And yeah, those diffraction spikes are very different to the usual ones we see.
Cheers,
V
The best target, not easy, not impossible and a very pleasing outcome.
Get on top of calibration and it will magically improve on it's own.
Great job.
muletopia
22-11-2022, 11:42 PM
Well I created a series of flats , created a master flat.All my gear is permanently mounted. I added the flats to the APP set of files and it in due course spat out another
image. I really an only see a small difference.
Anyway I attach this new imagw . A kind soil might criticise it,please.
Chris
xelasnave
23-11-2022, 07:59 AM
I would like to believe that I am a kind soul but I can not critise your image as I think you have done a great job as personally I find the Helix a most difficult object to capture and therefore can only say well done.
Alex
Dave882
23-11-2022, 12:17 PM
Nice job that’s really good! - the background is noticeably flatter and the dust motes are gone but still a couple of artefacts coming through so might be a different issue here (maybe some muck in the image train that shifted within the course of the session or between sessions)? Was the processing done exactly the same? To my eye I think the level of detail was slightly better in the previous version.
With APP my general process is after stacking:
-Crop
-Correct light pollution (also calibrates background at same time)
-Calibrate star colours (try diff options and settle on what looks best)
-star reduction (rarely used)
-saturation/contrast/sharpen in small (emphasis on small) measures
muletopia
23-11-2022, 10:55 PM
Thank you Alex for your kind words.
Thank you David for your tips on the tools to use after stacking. I used them all except the contrast/sharpen as I could not see the appropriate buttons.
Any way attached is the improved (in my opinion)image
Chris
Dave882
23-11-2022, 11:35 PM
Nice one yea I agree that’s better. Wow your Mewlon is super sharp! Much of the final presentation comes down to personal preference, but if it were me I’d decrease the stretch intensity (max 15% for small data set or 20% for more integration might be ok), push the contrast up a bit to neutralise some of the background inconsistencies and light touch of saturation/sharpen. All these can be found in the toolbar that’s on the RHS of the image preview.
Regarding the background noise, APP doesn’t have any denoise function so it’s either extra integration or pull the file into another program to finish it off.
muletopia
25-11-2022, 09:49 PM
Well I used David's hints and another image was produced, perhaps better back ground than the the previous attempt.
By way if capture back ground, this is a stack of 25 10 minute shots with a QHY8l camera, gain 0 and temperature -20 degrees. For the Melon 250 this gives 0.803 arc seconds per pixel.
So next year I will try to gather another 30 or so frames, that should reduce the noise.
Chris
Anth10
26-11-2022, 01:21 PM
Really like this rendition Chris. You’ve managed to produce a very respectable Helix one that you should be very satisfied with.
Well done!
muletopia
29-11-2022, 09:34 AM
Thanks Anthony for taking the time to view and comment, your kind words are appreciated. Some things bother me about the image, I will try to address them with more and different data.
Chris
Dave882
29-11-2022, 09:43 AM
Nice job Chris! I still think there's more that can be done in APP to flatten that background. LP/gradient removal is APPs strong-suit and it does it very very well. In the Tools>Light Pollution Removal, use lots of little boxes in every 'background-sky' part of the image, even in between the nebulous regions.
muletopia
29-11-2022, 11:56 PM
From your last tip I made 15 boxes in remove light pollution.
I am reminded of the song "little boxes on the hillside"
Yes the back ground is better controlled )i think)
Comments on the attached image appreciated.
Chris
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