Omega Centauri

[batema]

Hi,

After and endless amount of rain SE Queensland has been blessed with fine weather so I thought I would have a go at this amazaing cluster.

Taken with a William Optics Flt 110 on EQ6 Pro with a Qhy-9 at minus 20c. Guided with PHD and stacked in DSS and processed in Photoshop CS4. I would love some suggestions for improved image processing if possible. It is 60x1 min lum at 1x1 binning and 30x1 min RGB at 1x1binning. I have not taken any flats as I am still to work that out. The first image is not cropped and the second is cropped.

Thanks.

Mark

[jones]

Way to go! That looks fantastic. Good job!

[DavidU]

Nice ! I think it's a great tight shot, focus looks spot on.:thumbsup:

[ballaratdragons]

Absolutely stunning!

[Suzy]

Wow, what a beautiful shot! :)

[gregbradley]

Nicely framed, you got the exposure done well. Stars though lack any colour and a hint of a green bias to the image.

Try evening out the histograms for the various colours using levels.

Then boost the colour saturation to see if you can get some colour in the stars. Perhaps lowering the curves of the stars a tad may help bring some colour back into it as well.

I just had a play around with it and the colours are there and come up nicely. Nice yellow and blue stars.
When you stretch you weaken colours. So you will need to increase saturation before a curves stretch to compensate.

Greg.

[batema]

Thank you all for the feedback.
Greg if you read this you may think I'm nuts with my processing method. I do not know if it is right but I use photoshop to align my RGB and then boost that until I have a fairly vibrant slightly blurred image and seperately I process my Lum until I'm happy then I copy my colour onto the lum then align using luminosity then colour and adjust %. Then flatten and do some more stuff on the combined. Is this madness or is this sort of OK.

Mark

[Octane]

Mark,

That sounds like madness.

What software do you have available to you? This should ideally all be automated with MaxIm DL or CCDStack or Nebulosity, or what have you. Shouldn't DeepSkyStacker be doing the alignment/registration for you?

Align your RGB frames against your luminance (as that's where all the data is). Then, by all means, take each plane into Photoshop and play to your heart's content. At least that way, you don't have to mess around with aligning stuff in Photoshop -- this will remove the chromatic abberation-like artifacts around the bigger stars, too.

But, I do like what you've presented here, sans green bias.

Go back and reprocess! :)

H

[gregbradley]

Some use Photoshop for combining and aligning subs. I think other software does a better job. The problem with using Photoshop is
what if the image is rotated? Or needs to be scaled slightly in case one filter makes the image a fraction bigger or smaller?

You can use the Transform function (control T) to manipulate the image.
Move the central axis point to the spot where the rotation obviously centres.

I use CCDstack and the ccdisp alignment plugin. It minimises colour bleed in stars from not accurate enough alignment and that gives more pleasing colours.

As far as blurring rgb layer. A lot do that. I suppose the logic is colour does not have sharp boundaries like luminance does. Blurring softens the colour edges and reduces noise. I haven't done that and perhaps I should at times. Occassionally I get a data set where say blue has sharp boundaries for some odd reason. My Baader filters did that a lot. Hard to process out and blurring an rgb layer and especially the blue would have helped.

A common workflow is:

1. Callibrate and align in another specialty program like CCDStack or Maxim DL.

2. Photoshop for processing the images with the help of various plugins to make life easier.

I usually do a colour combine in CCDStack but it doesn't always do such a great job of this and can be a problem area of my workflow. CCDStack colour combine is the weakest aspect of CCDstack in my opinion.

Greg.

[Paul Haese]

Good star separation and the crop looks pretty. I agree with Greg though, slight green caste to the image and the star colours need a little work. Some slight work and it will be a ripper.