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Narrowband

Crescent to Tulip, in the Cygnus Star Cloud.


ollypenrice

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Taken this week with guest Paul Kummer. Here the processing is mine. It's a 2 panel mosaic in HaRGB using the house 'twin Tak FSQ106' rig and Mesu 200. Ha was with Tom's Atik 11000 and RGB with Yves' SXVH36. The 3Nm Ha looks after the mass of stars in the star cloud but it all gets more difficult trying to control them in broadband! Total integration just over 22 hours. Higher res Crescent data has been very gently applied.

Ha... (Bigger https://ollypenrice.smugmug.com/Other/Best-of-Les-Granges/i-6vDkdgm/0/X3/Cocoon%20to%20Tulip%20Ha%203Nm-X3.jpg )

Cocoon%20to%20Tulip%20Ha%203Nm-L.jpg

HaRGB...

Cocoon%20to%20Tulip%20HaRGB%2022%20hours

Bigger HaRGB  https://ollypenrice.smugmug.com/Other/Best-of-Les-Granges/i-dwsBgd9/0/X3/Cocoon%20to%20Tulip%20HaRGB%2022%20hours-X3.jpg

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I hope some of the narrowband imagers will have a go at this. We don't have the ultra tight OIII filter to go with this and on the star cloud I think balanced filters would be necessary. I've imaged the lower half before at 7 Nm and the 3Nm is really vastly better with smaller stars and more contrast in the structure.

Olly

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I really like the composition of this, the two main features in the corners gives it a really nice framing in my mind. Just looked this up and it would require a 2x2 pane mosaic for me - I was hoping to move away from mosaics!!! But perhaps you've given me an idea...... I'd like to say thanks, but I really don't mean it....... more targets added to the ever growing list :(

A pair of great images - I can't decide which I prefer. A self confessed mono junkie for sure, but that colour one has something rather nice about it :)

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liking the mono alot.

For me, The larger blue stars are a bit overpowering. Please note, this is a comment on my preferences, not on Ollys image. I'm in no position to tell him how to suck eggs :)

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liking the mono alot.

For me, The larger blue stars are a bit overpowering. Please note, this is a comment on my preferences, not on Ollys image. I'm in no position to tell him how to suck eggs :)

No, I agree. I'll ease them down a tad. Just a bit worn out by late nights!

Olly

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Excellent olly.

The framing is beautiful and as someone wrote it draws your eyes across the image. It's like finding two treasures in each corner too as you scan your way through it.

Think I prefer the ha version too.

Sent from my iPhone using Tapatalk

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As said, wonderful framing of a beautiful pair. Coincidently I recently imaged the bottom half of this composition. I like the Barnard dark nebulas/structures in that area. I envy your 3 nm Ha filter. The difference with a 7 nm is quite obvious. 2 hours (8x 15 min.) from a mag 18.5 sky with a Tak e-180 + Atik 11000.

b146_1000_20150709.jpg

And an annotated version (overlay courtesy of E.E. Barnard).

b146_1000_anno_20150709.jpg

See you soon! ;-)

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As said, wonderful framing of a beautiful pair. Coincidently I recently imaged the bottom half of this composition. I like the Barnard dark nebulas/structures in that area. I envy your 3 nm Ha filter. The difference with a 7 nm is quite obvious. 2 hours (8x 15 min.) from a mag 18.5 sky with a Tak e-180 + Atik 11000.

b146_1000_20150709.jpg

And an annotated version (overlay courtesy of E.E. Barnard).

b146_1000_anno_20150709.jpg

See you soon! ;-)

Lovely to see Barnard's annotation there. One of my astronomical heroes.

Indeed, see you soon.

Olly

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I'm intrigued by the dark "finger" shape extending from the centre of the image down to the bottom right which is clearly there in the Ha, but far more obvious in the HaRGB.  There's a similar dark triangular patch just above and right of centre too.

For me the Ha seems to give more definition to the fine structure, but adding the RGB really shows off the incredible density of stars, so they both appeal to me for different reasons.

James

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stunning images, it's probably an optical illusion but the mono shows more detail to my eyes 

Sadly the extra detail in Ha isn't an illusion. I say 'sadly'  because I'd love to be able to image in natural colour while retaining the fine structures selected from the broadband spectrum by the narrowband filters. However, I can't see any way of doing this. The 3 Nm Ha selects just the hydrogen, not even the nitrogen lline close to it, so the hydrogen structures are bound to show best in that filter. And any structure will always show the hightest contrast in black and white. Added to that, the 3 Nm filter holds down the stars to such an extent that, frequently, there is no star in an image field on which it's possible to run FWHM so you have to slew away.

I think an analogy might be to imagine recording a dinner table conversation involving three couples, each couple simultaneously speaking a different language. If you recorded all three languages in the mike you'd get no great idea of what any of them was saying. But if you used a filter which only passed one of the languages you'd at least know what one couple was saying.

One thing I would like to try, though, would be to make an Ha-OIII-OIII image using the matched Astrodon OIII (which we don't have) and combining this with RGB.

Why not pure false colour narrowband? I don't know. I'm glad other people do it but I'm really motivated, personally, by the natural colours of nature, or as close as we can get in this game.

Olly

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For me the Ha seems to give more definition to the fine structure, but adding the RGB really shows off the incredible density of stars, so they both appeal to me for different reasons.

Yes, as is so often the case the two images complement each other.

Nice to see the annotated Barnard's above. I've had little success matching them up as the online catalogues available just list the coordinates, but I believe the latest version of Stellarium now includes the Barnard catalogue.

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No, I agree. I'll ease them down a tad. Just a bit worn out by late nights!

Olly

Just my opinion, but I wouldn't tone down the blue stars too much.  They establish a context in color palette that makes the overall redness of the image seem more real and convincing.

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