Jump to content

NLCbanner2024.jpg.2478be509670e60c2d6efd04834b8b47.jpg

NGC6888 (Crescent nebula) and PN G75.5+1.7 (Soap bubble)

swag72

By swag72
in Imaging - Deep Sky

Recommended Posts

swag72

swag72

Posted
Posted

This is a Bi colour image of NGC6888 (The Crescent) and PN G75.5+1.7 (The Soap bubble). There's also IC4996 in there, a small open cluster below and slightly to the left of the soap bubble.

I really didn't get as much data as I'd set out to, due to the weather. I'm an impatient soul and the clouds always seem to beat me into submission!

Details

M: Avalon Linear fast reverse
T: Takahashi FSQ85 0.73x
C: Atik 460EXM 3nm Ha and OIII filter

10x1800s Ha, with bias and flats.
14x1800s OIII with bias and flats

Total integration time - 12 hours.

post-5681-0-00124400-1381823594_thumb.jp

A full res version can be found here - http://swagastro.weebly.com/uploads/2/3/3/7/23377322/ngc6888_completed.jpg

Link to comment
Share on other sites
  • Replies 35
  • Created
  • Last Reply
symesie04

symesie04

Posted
Posted

Its gorgeous Sara, absolutely packed with detail. Think 12 hours would be an ordeal in most peoples books but you do seem able to complete marathon equivalent projects. A lot of the smaller stars appear quite green on this monitor, is that a result of Bi colour? or just a inevitable part of processing?

Link to comment
Share on other sites
badgers

badgers

Posted
Posted

You've done wonders with that OIII shell and the soap bubble has come out beautifully too.

Lovely job.

Don't grumble about the spanish weather, or we'll make you move over here for 6 months!

I've been waiting 3 weeks for clear skies to get more OIII for this one. : )

Link to comment
Share on other sites
swag72

swag72

Posted
  • Author
Posted

Thanks all for your comments. I'll have a look at the stars again, I didn't think they were green, but you never know!! At times after processing these things, you can't see the wood for the trees!

I would have liked much more data - Maybe next year!!

Link to comment
Share on other sites
ollypenrice

ollypenrice

Posted
Posted

Yes, it's the Bubble that grabs me first as well. The combination of sharp focus and optics, long integration and the 3Nm Astrodon have made it stand out unambiguously. For anyone not familiar with it, don't expect to see it like this very often! And, yes, the weird O111 shell is super as well.

Olly

Link to comment
Share on other sites
swag72

swag72

Posted
  • Author
Posted

Thanks Steve and Olly - Appreciate you looking and commenting. Olly knows that this went through one or two reprocesses!!

Feel bad now i said that. Really could just be this monitor. But maybe just the Bi colour from the OIII. But cant say enough just how beautiful the detail is.

Don't feel bad, if you think it's green then it's worth saying. I welcome any types of comments from you all, they're all equally as valid. After all, if no one points out issues, then how will we ever learn and progress?

Link to comment
Share on other sites
steppenwolf

steppenwolf

Posted
Posted

A lot of the smaller stars appear quite green on this monitor, is that a result of Bi colour? or just a inevitable part of processing?

Feel bad now i said that. Really could just be this monitor.

Don't feel bad, accurate star colours are not that well produced using the bi-colour technique so you can expect to see some 'interesting' hues although on this occasion, I suspect that your monitor is skewing the blues a little.

Link to comment
Share on other sites
symesie04

symesie04

Posted
Posted

It must be these work Eizo monitors as no one else has mentioned it. Just odd as i have looked at it on two different monitors. Half the stars are a a lovely red and orange including the bright star next to the bubble but the other half have a green hue thats the same hue as the faint shell of the crescent and nebula around the bright star. Will have to have another butcher on my home pc.

Link to comment
Share on other sites
symesie04

symesie04

Posted
Posted

Yes that is a little better Sara. But sure these monitors are to blame as i sent a copy to my better half and asked her what colour the stars looked and she did say bluish without prompting. Hope its the monitors anyway or im going colour blind :(

Link to comment
Share on other sites
davew

davew

Posted
Posted

Really nice image. The Ha just glows. There aren't many renditions that give this appearance of being close by.

With regards to colour, an OIII filter more or less hits the cross over point of Green and Blue. Teal blue I think. This gives a marginal step towards Blue. I looked it up ( As I do ) and in PS it would be  approximately 24 . 167 . 181. In a Hubble pallet the OIII would always be Blue I suppose but in false RGB Teal Blue is much closer to reality ?

HLVG tends to remove the green content and when you realise how long Sara has spent getting it, that would be a great shame. You could use selective colour and alter the Green element. I think this fear of Green in an image is a bit of a fashion thing, although I think it's fair to say that Green backgrounds or gradients aren't good ! 

I rather liked the tinge of Green in the Crescent but that's just me :)

Then you have the problem of Internet Explorer boosting the colours !

Dave.

Link to comment
Share on other sites
swag72

swag72

Posted
  • Author
Posted

Thanks for continuing to look at this one folks.

To answer a couple of questions.....

@Earl - no plans for HST on this one, I actually don't like the colours that seem to come out of it - Sounds odd coming from me I know!

@ MeyGray - I definitely think there's more detail in 1800s subs compared to 900s. I don't do anything less than 30 minute subs for narrowband images, and if I want the faint stuff I'll do 30 minute luminance subs too.

@Dave - I did struggle with the amount of green in this image, especially as I always bang on about green, green, green and there's no green in space! But my get out is that it's not as a gradient across the image or a general tinge - Just green in the right places it would seem!!

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.