Sidonio inspired NGC5128

[rmuhlack (Richard)]

Inspired by the ground breaking image of Centaurus A by Mike Sidonio (see here), i decided to focus on NGC5128 as my first major project with my new Vixen VC200L. This is potentially still a "work-in-progress" as there may be some clear weather this week to add to the data set, but i have been itching to get some feedback, so here goes...

This is a HDR image of 95x5min and 28x10min subs taken over five nights last week with a modded Canon 400D, during the brief windows each night between moon set, sunrise and breaks in the weather.

I look to have a tilt (or possibly collimation) issue in the top left of frame (much more obvious in the astrobin hi res version), but overall I'm very happy with how this is coming along, especially considering as I am using an uncooled 12bit DSLR.

The first frame is a more mainstream rendition, while the second is my feeble attempt at "ultra-deep" - well as deep as one can go with my gear and level of imaging and processing experience (which is about 12 months). Processed with Pixinsight

The third is a comparison between my deep frame and a crop of Mike's image. I'm very pleased to see that some of the background 'galactic cirrus' that Mike captured so well looks (to me anyway) like it might be starting to come through in my deep frame if i imagine hard enough, albeit with significantly more noise in my example.

Critique welcomed, particularly any insights into what might be going on in the top left of frame (if it is tilt caused by my DIY mod, one idea i had was to try focusing on a star between the centre of frame and the top left corner, rather than in the dead centre, to either lessen or spread the effect across the frame), or how I can bring out that faint background dust without the associated noise.

Hi res version of the 'regular' shot here: http://www.astrobin.com/38483/

Hi res version of the 'deep' shot here: http://www.astrobin.com/38484/

Thanks for stopping by

[batema (Mark)]

Wow. MAGNIFICENT. The only thing i would try would be a high pass filter to contrast the central dust lanes. Fantastic image.

[gregbradley]

What a remarkable image! The fact you used a modded DSLR is even more remarkable.

Top shelf image.

Greg.

[strongmanmike (Michael)]

...wow very flattered

Fine result indeed Richard and very deep

It does look like your processing has produced a sort of dark ring around Cen A's halo..? What do you think? Might just be the HDR?

I have to say when I completed that image in mid 2008 I thought for sure with time many others would be producing similarly or even deeper images of this iconic galaxy, in a similar way that images of M81/82 have become deeper end deeper....but it seems clear it is not so easy to achieve

Mike

[batema (Mark)]

What does going "deep" mean?

[RobF (Rob)]

Isn't that a technical term for a !@#$-load of data, preferably collected from an extremely dark sky site?

Fantastic and inspiring image Richard.

[strongmanmike (Michael)]

Originally Posted by batema

What does going "deep" mean?

To me it is when you reveal faint extended features that are below the level of the natural sky brightness, particularly from a true dark sky, rather than seeing fainter and fainter stars (although this is part of it too)

Mike

[rmuhlack (Richard)]

I has been exciting to see how the image has come together as I have collected data each night, and as I gain more imaging experience I'm constantly amazed at what this little camera can pick up. My excitement finally spilled over and so I had to share what I had so far so thanks for all the encouragement folks.

Originally Posted by strongmanmike

...wow very flattered

Fine result indeed Richard and very deep

It does look like your processing has produced a sort of dark ring around Cen A's halo..? What do you think? Might just be the HDR?

I have to say when I completed that image in mid 2008 I thought for sure with time many others would be producing similarly or even deeper images of this iconic galaxy, in a similar way that images of M81/82 have become deeper end deeper....but it seems clear it is not so easy to achieve

Mike

Thanks especially for your comments Mike - your image is still the touchstone The dark ring you refer to is actually there in my non-HDR images from earlier in the imaging run (as I did the 600s subs last). For example, the attached is a quick and crude process of just the 300s data, and it's visible here too.

I can maybe see some of those darker areas in your image but clearly not as obvious as in mine. My processing is no doubt partly to blame (im still learning after all) - i'm using curves to progressively stretch a *very* small/narrow variation in luminance just above the background level, so maybe there is a better way?

Another thought I had was that there may be differences in wavelength response between the two cameras which means that the 'ring' around the halo isn't captured as strongly in my image...?

The scary thing is that now I seem to have that tilt more under control (after some tweaks over the last couple of nights) I'm tempted to do it all again...

Addictive isn't it