Ngc 6744

[gregbradley]

One of the most beautiful galaxies in the sky NGC6744 is one I imaged recently but never was happy with the processing.

I reprocessed it and got a far better result.

For some reason there was a green gradient in the data - perhaps some misty thin cloud at one point. Thanks to Russell Croman's gradient Xterminator it was handled.

7 hours LRGB STL11 camera, RCOS 12.5 inch, Astrodon filters from my dark site observatory at 770 metres altitude which is quite high for Australia.

http://www.pbase.com/image/96539963

Greg.

[jase (Jason)]

Lovely Greg. The far reaching arms show an interesting array of details. Did you use the self healing brush to get rid of the green filtered line at lower left? A mask may have been a better approach. Well done on this reprocessed version.

[Ric]

Lovely image Greg, very intricate in it's detail.

[AlexN]

very nice indeed I love how much detail there is in the arms, and also how far some of the arms extend..

Very well shot and processed.

[gregbradley]

Hi Jase,

I used the clone tool. A satellite went through a green sub.

How would you use a mask to get rid of a satellite trail?

Greg.

Originally Posted by jase

Lovely Greg. The far reaching arms show an interesting array of details. Did you use the self healing brush to get rid of the green filtered line at lower left? A mask may have been a better approach. Well done on this reprocessed version.

[Dietmar]

hi Greg,

what a beauty!
your result looks very esthetical to me.
would be interesting to see the first atteptms to compare with, though.

[iceman (Mike)]

That's a lovely result, Greg. Beautiful details in the extended arms, and quite a rich starfield!

[Garyh]

Beautiful and deep image Greg!
Very faint outer arms clearly visible
made me look at my attempt last year and these are not visible at all with a hours exposure!
Great work!

[jase (Jason)]

Originally Posted by gregbradley

Hi Jase,

How would you use a mask to get rid of a satellite trail?

Greg.

One approach would be to duplicate the layer
Gaussian blur the new layer heavily
Create the mask and brush it in with an opacity of 20%
The Gaussian blur will likely make the mask very smooth, so add some noise to it.

Or you could do something similar.
Duplicate the layer,
Gaussian blue the background layer
Use the lighten blend mode on the duplicated layer to bring back the details, then erase the defects bringing the Gaussian blurred layer through.

The trick with masks is to go easy on the brush opacity. 100% can be rather coarse and does not provide a smooth transition. Also, you can Alt+left mouse click the mask to work specifically on it. This is great as it allows you to blur the entire mask that you are applying.

The problem with the clone tools is that is rather abrupt. If you want to use it, do it early in the routine or at least before noise reduction. Sometimes its easier to correct combined sub before the colour combine routine. A query however, how many green subs did you take? This should have ultimately been removed with the combine function as it would be classified as outlier pixels.

[Alchemy (Clive)]

very nice greg , good color and detail in the inner arms, good to see its not overdone in the core

[sjastro]

You did a good job Greg on processing a very difficult target.

Regards

Steven

[Bassnut (Fred)]

Nice effort at the full view Greg, lots of colourful stars.

[Dr Nick (Nick)]

Wow, that's spectacular! I wish I could get images like that!

[gregbradley]

Thanks for the tips Jase and thanks for all the compliments. Its nice to be part of an astro imaging oriented group.

Greg.

Originally Posted by jase

One approach would be to duplicate the layer
Gaussian blur the new layer heavily
Create the mask and brush it in with an opacity of 20%
The Gaussian blur will likely make the mask very smooth, so add some noise to it.

Or you could do something similar.
Duplicate the layer,
Gaussian blue the background layer
Use the lighten blend mode on the duplicated layer to bring back the details, then erase the defects bringing the Gaussian blurred layer through.

The trick with masks is to go easy on the brush opacity. 100% can be rather coarse and does not provide a smooth transition. Also, you can Alt+left mouse click the mask to work specifically on it. This is great as it allows you to blur the entire mask that you are applying.

The problem with the clone tools is that is rather abrupt. If you want to use it, do it early in the routine or at least before noise reduction. Sometimes its easier to correct combined sub before the colour combine routine. A query however, how many green subs did you take? This should have ultimately been removed with the combine function as it would be classified as outlier pixels.