Centaurus A - NGC 5128

[whale (Nicholas)]

This Centaurus A image was taken at Eldee Station in outback NSW near Broken Hill whilst on a roadtrip with some astrophotography mates

Thanks for looking!



Higher res version here:
https://www.flickr.com/photos/nichol...ream/lightbox/



Scope: Orion Optics UK, focal length 1700mm f6.7
Camera: QSI583 WSG with a Loadstar X2 off axis guider
Acquisition: 25 x 5 mins luminance, 12 x 5mins each RGB

Mount: Astro-Physics 1100gto
Camera cooling: -20c
Image scale 0.66 arc seconds
Processed with CCDStack 2.0

[RickS (Rick)]

Very nice, Nicholas. Good detail. Colour is a little muted for my taste, but I do lean to the extreme The only minor nit was a few stray brightly coloured pixels.

Cheers,
Rick.

[Atmos (Colin)]

It is a pleasing result I do agree with Rick, you could push the saturation a but further than what you have. I do also tend to be a bit heavy handed after a couple of processes

[strongmanmike (Michael)]

Nice one Nick, good to see the ODK doin its stuff

Mike

[cazza132 (Troy Casswell)]

That is a really nice crack - the stars add to a 3D feel. I like the diffraction spikes - subtle and adds to the star colours. Good detail with the trans-galactic dust also. A little warm with colour balance - with correction you can push the saturation. A very solid shot!

[Andy01 (Andy)]

Looks great Nick, very sharp & clean, well done

[phomer (Paul)]

Nick,

I think you have done an excellent job of bringing out the halo and think that pushing it any further would only bring out additional noise.

The image definately shows off the excellent sky conditions.

Regards

Paul

[whale (Nicholas)]

Thank you all very much for your comments and critique

I'm going to beef up my bias and darks library and see if this helps to eliminate/reduce those odd primary colour pixels that have made it through to the integrated image. If worthwhile I'll post the 2nd version.

again, thanks four feedback

cheers

Nick

[Geoff45 (Geoff)]

Originally Posted by whale

Thank you all very much for your comments and critique

I'm going to beef up my bias and darks library and see if this helps to eliminate/reduce those odd primary colour pixels that have made it through to the integrated image. If worthwhile I'll post the 2nd version.

again, thanks four feedback

cheers

Nick

Nice Nick. As others have said, a bit of a saturation push is worth trying. The odd pixels may not go with darks, since the sensor may have some colour dependence, while the darks are unfiltered. Have you tried using the bad pixel map in CCDStack? It usually works quite well.
Geoff

[gregbradley]

Nice image Nick. I like it. Getting up to date biases and darks probably won't handle the odd colour pixel. Not sure where those little buggers come from but they are common in processing. Sometimes very few. Usually data rejection done well gets rid of most.

But simply going around the image a bit zoomed in with the spot healing tool set to a small circle and click on them gets rid of them easily. Usually I see a few and occasionally none. But I look for them in every image I do just about just in case.

Something is off with your optics a tad. The corners of the images are showing coma with the small 8300 sensor. This may mean collimation, or your primary and secondary mirror spacing is off a little. Something. Its not tilt as it seems equal on all 4 corners. I am being very picky here as it is not very visible. I am correcting something similar on my setup so I notice these things at the moment.

Also you need to crop the image a bit as the edges show some of the usual slightly misaligned subs that you have to crop out near the end of your processing a stack of images. Its a part of processing every stacked image to crop off that little rough edge where small parts don't align.

A bit more saturation and some selective sharpening (sharpening only the brighter detailed areas using a mask) would enhance this fine image more in my opinion. The data is there. Enhancing the blue spray of the star making area usually brings this object up. The jet may also come up if its in the data.

Greg.

[whale (Nicholas)]

Here's an update version of this object.



https://www.flickr.com/photos/nichol...ream/lightbox/

• An up to date bias master that comprised of 80 subs.
• A dark subtraction that's based on 40 dark subs instead of just 17.
• I've applied a saturation bump
• Some sharpening that was applied just to the core
• Smoothing to remove the "pixelation look" that was evident in the mid-tones
• cropped out the 1-2 pixels of the edge to remove the non-over-lapping region.

This one is based on:

I've enjoyed this experience, thank you all for your feedback.

cheers

Nick

[mbaddah (Mo)]

Amazing! Gotta be happy with that.

[astronobob (Bob)]

A good solid Image Nicholas.
A favourite galaxy and a great show