M31 luminance WIP - HELP REQUIRED!

[x6gas]

Hi all,

I need some help!

In my quest to capture the Messier catalogue spirals, I turned my Baby Q on M31 last night.  I really should have swapped out my 490ex for my 383L - I've pretty much been holding on to the 383 specifically for this target, but I was tired and couldn't bring myself to go through the process of making the 383 parfocal with the OAG guidecam.  So I can fit most of it in, but it's a bit unsatisfactory and I probably will go again at some point...

Anyway, I am having some trouble sharpening the image up - especially tthe dust lanes - and I would welcome some suggestions as to how to process this.  With so many stars, a high pass filter gets pretty ugly, pretty quickly.  Is it a case of patiently masking out all the little bleeders, using a star mask to do the job, deleting a star layer so I can work only on the galaxy, or what?

Not a perfect night, but the data seems reasonably good so if I can crack the processing this will eventually be a Lum layer for LRGB, if I ever get the colour data.

Scope: Tak FSQ 85EDx

Mount: CGEM DX

Camera: Atik 490ex

Guiding: Atik OAG; PHD; QHY IMG0H

36 x 300s for a total integration time of 3 hours.

Thanks, Ian

[nmoushon]

I had the same problem with mine. I tried to do layer masking like I would for M42 to get the dust lanes to pop more to begin with. Then I did normal processing then my high pass filter and blotted out the bright stars as you did. This way I wouldn't have to do the high pass filter as hard to get the wanted effect of the dust lanes popping out. Also less bloat added to the stars I didn't blot out because I didn't think they were bright enough or I missed them. This was with my DSLR data mine you so might work a bit differently with CCD data but thought I'd share.

[davew]

A trick you could use is layer mask - hide all.

IF I can remember ........

Make a new layer and use your high pass on it. Then create layer mask - hide all and change it to overlay. Now the image looks like just the background. Use the eraser at a very small size and paint just the bits you want to sharpen, dodging the stars. Then go to blur - Gaussian blur and make the holes a bit blurry so as not to have sharp edges. Use opacity to reduce the effect to taste.

There are a few web pages about to show this if I got something wrong. I can do it better than explain it

Dave.

[symesie04]

Cant help with the processing im afraid, other than say isnt there a tutorial in annies actions for quick masking of stars. Think she even uses M31 as an example.

http://www.eprisephoto.com/videos

What i can say is the data so far looks yummy and im looking forward to seeing the finished article.

[ollypenrice]

The quick answer would be to use Noel's Actions, now called something else but found here; http://www.prodigitalsoftware.com/Astronomy_Tools_For_Full_Version.html

Enhance Local Contrast is the one you want, always used selectively as a layer. This action tends to black clip so make sure you have lots of room to the left of the histogram pedestal available before applying it. Noel also has a star selector which is an incredible time saver, thuogh if you want to do it yourself there's a first class Martin B tutorial on here.

Putting your own little kinks into the curve can be very powerful. Bringing the dark dust lanes down while lifting the immediately outlying region up a tad would help separate them.

Olly

[x6gas]

Thanks all for the advice.  Plenty to try!

Ian

[x6gas]

Thanks again for the replies.

Olly's suggestion of running the Local Contrast Enhancement action from what is now called Astronomy Tools seemed to help.  In fact, I ran three iterations, with a Space Noise Reduction in between and it has definitely improved definition (I already had this action set, but had never tried that particular routine - or at least if I did I hadn't really clocked its potential...)

Anyway, I will go back I try the more complicated processing suggestions, but here's where I've got so far.

I need to redo my flats as I have an artifact top right...

[davew]

That's coming on a pace.

I knew there was a good video out there on the process I mentioned and now I've found it.

http://imagingdeepsky.com/Presentations.html

All I would say is go gently I think Ken can be a bit wild at times but at least he puts stuff out there for the rest of us.

Dave

[davew]

I've just realised that I didn't say which video to watch !

They are all very good but the one I was specifically meaning was " Depth of Field Processing "

You'll find Ken Crawford in the new and much touted " Lessons from the Masters "

Dave.