Struggling with comet

[Anthonyexmouth]

Well, I had a bash at some comet imaging and totally failing with the processing. Followed a few tutorials on YT but every time they look like S. Can anyone take a shot at this and see if they can get anything out of it. 

Cheers

Lights.zip

[Paul M]

I've downloaded the subs and I'm currently having a go, first with the ephemeris stacking tool in ASTAP, then I'll have a go with DSS.

The individual subs look like you have some nice comet in there! 

Watch this space...

[Anthonyexmouth]

2 hours ago, Paul M said:

I've downloaded the subs and I'm currently having a go, first with the ephemeris stacking tool in ASTAP, then I'll have a go with DSS.

The individual subs look like you have some nice comet in there! 

Watch this space...

Look forward to seeing what you make of it. 

[Paul M]

I'll show you mine if you show me yours... 🤣

Anyway, here is what I got with ASTAP and ephemeris stacking. The stacking went well. I think My default colour settings left the stars with an orange tinge I don't have the skills to remove!

So, saved as a TIFF and stretched in P.Shop. There is a gradient. left to right, that I can't repair without losing much of the fainter comet detail. I too struggled but I love playing with software so it's ben fun so far.

 

I'm going to hav a go with DSS now.

 

[Paul M]

I used DSS comet only satcking and comet+stars stacking.

Comet + Stars is always a compromise but somehow it's lost the colour info.  No colour to enhance! 

Comet only stacking gave a nice comet but I can't pull the stars trails out of the background. There were a good few poor subs (cloud?) that I didn't dump with ASTAP but did with DSS..

Anyway, that's me, hopfully someone who knows what that are doing will pop along shortly...🤩

 

exhausted.

[Marvin Jenkins]

Great work everyone. I don’t care if it is perfect or if it processed correctly. I saw this in the EP two nights ago and these images far surpass that. Although the view in the EP had more green.

Round of applause from me. I am loving this comet as I have actually seen it for once but so many people have different images of it. I hope you don’t mind me wrecking it with a smart phone pic if the clouds disappear.

Marv 

[ONIKKINEN]

Tried processing it, i think i went a little too far in some points and took some wrong turns with the stars somewhere along the line, but im not going back to that now that its done. I think i left the registration interpolation algorithm to some funny one that produces the weirdly aberrated stars with specs of different colours on the cores (dont zoom in too much). Also didn't care for the starless and star only layer so some of the stars (those behind the comet) are not that tastefully put in.

I used Pixinsight, Siril and Photoshop. StarXterminator and NoiseXterminator also used, so not the cheapest possible combination of tools. They are all replaceable by free ones though, just means that colour calibration cant be done in the linear phase (I think Starnet++V2 doesn't do linear images? Not sure about that).

First stacked a starstack with the comet position ignored (also rejected some as you have some bad subs here mixed with the good stuff, looks like clouds!) with aggressive clipping to remove as much of the comet as possible. Then comet aligned the already registered subs and stacked a comet only image with those, also with aggressive clipping to hide the inevitable walking noise from the smeared stars. Then ran the same crop and dynamic background extraction on both files and linear fit them afterwards. Then removed stars from the starstack with StarXterminator while the stack is still linear. Simple pixelmath "+" combination of the stars-only image from the starstack and the comet only image to create the stars + comet composite. I think this method of compositing has the least chance of causing sudden baldness due to stress, i have not had nearly as much luck with DSS or other dedicated comet+stars stacking methods that seem to simply not work or produce horrible messes of the stars (or a surprise grayscale image like above in a previous comment).

Since the composited data is still linear, it can be processed however you like. In this case i ran SPCC to colour calibrate(no SCNR green, wonder if i should have since stars ended up green too) . Stretched in Siril with Asinh stretch and histogram transformation and exported to Photoshop. In Photoshop i ran StarXterminator again to fix the inevitable mess that came from the stars being streaked (and your ampglow). The streaks and ampglow go away easily with the lasso tool and content aware fill since there is no background nebulosity to worry about. NoiseXterminator too at some point to reduce noise. Looking at the image now many parts of it look a bit artificial and could be improved, but this will do for now.

Pretty good data by the way, much easier to work than the mess i captured a couple nights ago!

[Patty]

Got this a few nights ago with my Celestron6se with HyperstarV4 15 mins total exposure. Live stacked with ASIAIR plus. Zwo Asi585mc camera. No processing just a stretch. 30 frames stacked 30sec exposures 254 gain. Azgti mount, no guiding. Tried to keep the exposure times down to avoid stretching the core.