The Dark Tower - Finished!

marc4darkskies (Marcus) · #1 10-06-2011, 08:40 PM

This was a tough one! I fought clouds and poor seeing for 5 nights over 10 days (the other nights were completely overcast). The guide star was faint for Ha (mag 9.9). I threw out a whole night's data (5.5 hours worth) because of poor seeing (FWHM >= 4 pixels). The object is dim and demands a reasonably large amount of data so this is a record for me - nearly 14 hours all up. Processing was a hard slog as well.

Anyway, I'm quite happy with how it's turned out, but may tinker depending on the feedback I get. There aren't many renditions to compare with either. Colour rendition varies quite a lot among other versions out there and none, apart from Rob Gendler's LRGB and Don Goldman's LHaRGB versions, effectively render the reflection nebs at the top of the tower to their fullest extent. It's these refl nebs that make this image IMO, and to appreciate them you need to view at full res.

Hopefully I've done justice the raw LHa version I posted earlier too. Let me know what you think!

Small:
http://www.pbase.com/gailmarc/image/135434539/large

Large:
http://www.pbase.com/gailmarc/image/135434539/original

Cheers, Marcus

leon · #2 10-06-2011, 08:48 PM

Well Marcus, what you described seems to have been a hell of a struggle, and it appears you won, very nice indeed, you came out a winner, well done indeed.

Leon

Hagar (Doug) · #3 10-06-2011, 09:01 PM

Looks very good to me Marcus, Very vibrant but thats what this one needs to bring out it's best. The little reflection neb areas have been blended into the huge emission nebula beautifully. I can only imagine how difficult this would be to get right without washing something out.

Beautiful.

strongmanmike (Michael) · #4 10-06-2011, 09:08 PM

Yeh justice done I think Marcus, great result

You are right, having the LRGB as well as the Ha showed up the reflection nebulae nicely.

I see you didn't bother tackling thosee iron cross halos, they are beauties

...can't say I have see those in your images before..?

Oh and I have absolutely no sypathies for your trials and tribulations one iota, with a remote automated dome and PME operated from inside a warm study, being able to throw away soft data is a pure luxury.. you are just winging & winning, so.... shut up!

Mike

h0ughy (David) · #5 10-06-2011, 09:26 PM

Quote:

Originally Posted by strongmanmike

Yeh justice done I think Marcus, great result

You are right, having the LRGB as well as the Ha showed up the reflection nebulae nicely.

I see you didn't bother tackling thosee iron cross halos, they are beauties

...can't say I have see those in your images before..?

Oh and I have absolutely no sypathies for your trials and tribulations one iota, with a remote automated dome and PME operated from inside a warm study, being able to throw away soft data is a pure luxury.. you are just winging & winning, so.... shut up!

Mike

i think mike is a little hormonal

great image, you look as though you have wrung out every photon.

DavidU (Dave) · #6 10-06-2011, 09:29 PM

Beautiful.

atalas · #7 10-06-2011, 09:30 PM

A wonderful result Marcus! dropping back to the small image I see a stunning composition

multiweb (Marc) · #8 10-06-2011, 09:53 PM

Quite a treat Marcus. The highres is great to browse around. Top effort considering the weather of late. Well done.

strongmanmike (Michael) · #9 10-06-2011, 09:59 PM

Quote:

Originally Posted by h0ughy

i think mike is a little hormonal

That's it! you always start on me David, we don't all have your sense of humour you know? You high falutin gringoes with domes and automated egg beaters sitting in your ivory automated dome towers..

...

...does my bum look big in these...?

Peter Ward · #10 10-06-2011, 11:16 PM

What's not to like?

Another well executed cool-wall candidate.

marc4darkskies (Marcus) · #11 10-06-2011, 11:16 PM

Quote:

Originally Posted by leon

Well Marcus, what you described seems to have been a hell of a struggle, and it appears you won, very nice indeed, you came out a winner, well done indeed.

Leon

Well I definitely had to work for this one that's for sure! Thanks a lot Leon!

Quote:

Originally Posted by Hagar

Looks very good to me Marcus, Very vibrant but thats what this one needs to bring out it's best. The little reflection neb areas have been blended into the huge emission nebula beautifully. I can only imagine how difficult this would be to get right without washing something out.

Beautiful.

Cheers Doug! Yeah, I love the little blue patches - Many emission nebs have them lurking somewhere.

Quote:

Originally Posted by strongmanmike

Yeh justice done I think Marcus, great result

You are right, having the LRGB as well as the Ha showed up the reflection nebulae nicely.

I see you didn't bother tackling thosee iron cross halos, they are beauties

...can't say I have see those in your images before..?

Cheers mate! No, even I won't try to remove those halos - an artefact I think of the vignetted field of the 1.6 extender

I should have framed it better so they were away from the edge of the field - but they don't look tooooo bad IMO.

Quote:

Originally Posted by strongmanmike

Oh and I have absolutely no sypathies for your trials and tribulations one iota, with a remote automated dome and PME operated from inside a warm study, being able to throw away soft data is a pure luxury.. you are just winging & winning, so.... shut up!

Mike

Oh now c'mon! Jealousy's a curse don't forget! Besides, having an obs, a PME, an air conditioned control room with Foxtel and a sofa can be a struggle ya know!

Quote:

Originally Posted by h0ughy

...
great image, you look as though you have wrung out every photon.

Thanks Dave! Yep, I think so too. I usually know when I've finished processing ... I spend an hour or two tinkering and nothing changes!

Quote:

Originally Posted by DavidU

Beautiful.

Cheers Dave!

Quote:

Originally Posted by atalas

A wonderful result Marcus! dropping back to the small image I see a stunning composition

Thanks a lot Louie! Framing and composition is just as important in astrophotography as it is in traditional photography (of course) and worth spendng some time getting right.

Quote:

Originally Posted by multiweb

Quite a treat Marcus. The highres is great to browse around. Top effort considering the weather of late. Well done.

Thanks Marc ... but DON'T talk to me about the weather!!!

...

marc4darkskies (Marcus) · #12 10-06-2011, 11:18 PM

Quote:

Originally Posted by Peter Ward

What's not to like?

Another well executed cool-wall candidate.

Thanks Peter! Pictures starting to spread down the hall now!

renormalised (Carl) · #13 11-06-2011, 12:04 AM

Absolutely stunning, Marcus

Excellent work...great detail and brilliant colour. I like the effect of the "streak" of neb coming down like a lightning bolt and hitting the tower...looks like it's what energises the tower!!

John Hothersall · #14 11-06-2011, 12:25 AM

I love this sort of dedication as the result is absolutely splendid.

John.

Ross G · #15 11-06-2011, 06:42 AM

Hi Marcus,

What an unusual and beautiful object and what an amazing photo of it.

Technically and artistically perfect!

Thank you.

Ross.

Phil Hart · #16 11-06-2011, 10:14 AM

superb work as usual Marcus. a treat for the eyes.

your red tones look very natural given the strong reliance on HA in the image. care to share any info about your preferred way of managing the HA in the image?

some of the stars embedded in the neb do look like they have unsharp mask dark halos around them, or is that just an affect of the HA layer as well?

cheers
Phil

marc4darkskies (Marcus) · #17 11-06-2011, 11:45 AM

Quote:

Originally Posted by renormalised

Absolutely stunning, Marcus

Excellent work...great detail and brilliant colour. I like the effect of the "streak" of neb coming down like a lightning bolt and hitting the tower...looks like it's what energises the tower!!

Cheers Carl! I hadn't thought of it that way but you're right, it does kind of look like that.

Quote:

Originally Posted by John Hothersall

I love this sort of dedication as the result is absolutely splendid.

John.

Thanks John, glad you liked it.

Quote:

Originally Posted by Ross G

Hi Marcus,

What an unusual and beautiful object and what an amazing photo of it.

Technically and artistically perfect!

Thank you.

Ross.

Thanks a lot Ross, appreciate that!

Quote:

Originally Posted by philiphart

superb work as usual Marcus. a treat for the eyes.

your red tones look very natural given the strong reliance on HA in the image. care to share any info about your preferred way of managing the HA in the image?

some of the stars embedded in the neb do look like they have unsharp mask dark halos around them, or is that just an affect of the HA layer as well?

cheers
Phil

Thanks Phil! I'm glad you liked it!

There is no unsharp masking of the stars. Blue stars in an Ha cloud invariably look like they have a dark halo. It's always an effect you have to try and minimise with an Ha blend of course. I could reduce the halos more by lowering the luminosity of the Ha, but I think I've struck a reasonabe balance for now. I may do some more tinkering though

Phil Hart · #18 11-06-2011, 12:24 PM

Quote:

Originally Posted by marc4darkskies

There is no unsharp masking of the stars. Blue stars in an Ha cloud invariably look like they have a dark halo. It's always an effect you have to try and minimise with an Ha blend of course. I could reduce the halos more by lowering the luminosity of the Ha, but I think I've struck a reasonabe balance for now. I may do some more tinkering though

Your tinkering may include trying to mask out the effect a little with a star mask but you've probably already tried that!? With your skill I've no doubt that you've balanced the processing well already!

marc4darkskies (Marcus) · #19 11-06-2011, 04:48 PM

Quote:

Originally Posted by philiphart

Your tinkering may include trying to mask out the effect a little with a star mask but you've probably already tried that!? With your skill I've no doubt that you've balanced the processing well already!

Always appreciate honest feedback Phil! Did a bit more halo reduction without changing the Ha luminosity much - should look a little better now.

Paul Haese · #20 11-06-2011, 05:19 PM

Great work Marcus. I like this rendition. Tones of red and pink look great. The reflection nebula looks great superimposed on the tower. Well done.

Quote:

Originally Posted by strongmanmike

You high falutin gringoes with domes and automated egg beaters sitting in your ivory automated dome towers

What about us with roll off roofs and our automated egg beaters?

Only sky time I have gotten lately is the finally sort my PME out. Now I want some sky for imaging.

Champing at the bit.