M83 after the moon set

[Dilsh]

Hey team,

One cloudless night!!! Really wanted to shoot a galaxy so took a few hours of M83 after the moon had set. Guiding was not great. I think there is a fair bit of high cloud in Melbourne these days. I also need to hypertune my mount when I am brave enough.

In the end I threw away alot of subs. This is 2 hours and 44 minutes. Took 60s subs to compensate for the light pollution with this broadband target.

Critique welcome.

Surely some clear skies are on the way!

D

[alpal]

Hi Dilshan,
I assume that's taken with your 925 edge HD? -

you have excellent data - you must have had good seeing?
Was it better than 2.5 arc seconds FWHM?


Critique welcome?
It's hard to judge it properly unless you posted say a 2 Megabyte version somewhere.
I'm guessing here but -
the processing looks a little over cooked -
it looks over sharpened and it has a touch of a green cast.
The Deep Sky HLVG Photoshop plugin would get rid of that.
The background is too dark and it's missing all the noise
as though it's been over smoothed.

cheers
Allan

[Dave882]

Mate there’s some incredible detail there well done! I do kinda agree with Allan’s comments re the sharpening but it’s a very fine line and zoomed in it looks really nice. Great work!!

[Dilsh]

Thanks Dave. Hopefully I get some more nights to add to it



Hey Allan,

Thanks for the comments.

Yes shot with the 925edgeHD. Not sure what my FWHM was but my RMS was around 1.5 arc seconds for the night when it is usually around 0.9 with the off axis guider. Hence the comment about poor guiding. I darkened the background to get rid of all the LP gradients. I have uploaded a version without that. I agree with you though, I think it looks better without darkening the background.

I have also attached a full res version as well as a google drive link. Hopefully that works;

https://drive.google.com/file/d/1acDVQBS_jyBV5DJHKM2I-rRiD5tDJ9GM/view?usp=sharing

[alpal]

Thanks Dilshan,
wow a 68 MByte file.
Looks very good.
That is some amazing detail in there.
It still might be worth a 2nd go at the processing?
What more can you extract from such good data?


cheers
Allan

[Dilsh]

Hey Allan,

Thank you. Will give it another go but will hopefully add some more data as well.

Cheers,

D

[strongmanmike]

Some nice contrast there Dilshan, I like the darker look, has an almost 3D quality, nice :thumbsup: The level of detail and resolution looks good too, what tools did you use for this aspect?

Mike

[Dilsh]

Thanks Mike,

I mainly shoot in narrowband given the LP from my backyard so still learning the best setting to shoot these broadband targets with.

I used a 294mm pro with LRGB Antlia filters. My 925edge HD sits on an EQ6r pro with a OAG using a 290mm (really good guide cam. Always finds a few stars!) I tried to deal with the LP by shooting only 60s exposures and only using the subs after the moon had set. I analysed the subs looking at the total number of stars and FWHM and deleting the outliers. Therefore I was only left with 2 hours of total exposure.

As far as processing goes,
Automatic background extraction - RGB channels combined, Blurx to RGB and L image, SPCC to RGB image, Starxterminator and Noiseexterminator to L and RGB, then generalised hyerbolic stretch to make images nonlinear, LRGB combination, some curves mainly for saturation, local histogram equalization for some more contrast and the HDR to control the core of the galaxy. Then combined starless and star images. Final SCNR to remove the green haze and histogram transformation do darken the background.

I might give it another go once I have some more data. I tried to not "blurx" it too hard but maybe I should have used less.

Hope that makes sense.

Cheers,

Dilshan