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Cave Nebula, widefield...

ollypenrice

By ollypenrice
in Imaging - Deep Sky

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ollypenrice

ollypenrice

Posted
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Taken with SGLer Pompey Monkey, this is an RGB plus Ha image. We had a few hours before a big moon appeared so shot RGB in both Taks first, then switched to Ha in both barrels. One side had a 3Nm Astrodon and the other a 7Nm Baader. Sadly the 7Nm wasn't worth using but the 3Nm was fine. We also blended in a little RGB and Ha from an incomplete shoot of the central part using the TEC140 last year. This has slightly improved the resolution in the Cave itself.

RGB 1 Hr 20 mins per channel. Ha 18x15.

Processed in AstroArt, Registar, Pixinsight and Photoshop.

CAVE%20HaRGB%20WEB-L.jpg

Full size; https://ollypenrice.smugmug.com/Other/Best-of-Les-Granges/i-G23htWB/0/O/CAVE%20HaRGB%20WEB.jpg

Olly and Paul.

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michael.h.f.wilkinson

michael.h.f.wilkinson

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Great image, especially for such a short RGB exposure.

I have spotted this in my C8, but it is very hard indeed. Funnily it was the dark patch that gives the Cave its name that gave its location away. This was a bit of an eye-opener for me, in that I suddenly realised something faint must be there because there was a dark spot where it was being obscured. I have used that trick many times on faint objects, where dust lanes within the object have more pronounced edges than the outer boundary of the nebula itself.

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PhotoGav

PhotoGav

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That's a nice image, especially considering that it is relatively light on data. Love the star colours!

What interests me most is your comment about the 7Nm vs 3Nm Ha data and that only the 3Nm was usable given all the moonlight. That sounds like quite an advert for 3Nm filters. An upgrade that I have on my wish list, but have not prioritised it - perhaps I should bump it up the list a bit?

The other interesting point is the blending in of data in parts of an image. No idea how you would go about doing that. Perhaps another reason why I need to visit Mr. Penrice?!

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ollypenrice

ollypenrice

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That's a nice image, especially considering that it is relatively light on data. Love the star colours!

What interests me most is your comment about the 7Nm vs 3Nm Ha data and that only the 3Nm was usable given all the moonlight. That sounds like quite an advert for 3Nm filters. An upgrade that I have on my wish list, but have not prioritised it - perhaps I should bump it up the list a bit?

The other interesting point is the blending in of data in parts of an image. No idea how you would go about doing that. Perhaps another reason why I need to visit Mr. Penrice?!

On this occasion the victory was quite simply a walkover for the 3Nm. The moon was a big waning gibbous and not on the opposite part of the sky. Sometimes there is little to choose, sometines the 3 is better or a lot better, on nebulosity. It always gives tiny stars, though, which is nice for standalone NB and also good for blending with broadband since the Ha stars never affect the stars in the red layer at all. I tend not to image during bright moon but if you wish to do so then it has to be the Astrodon. It is several times as moon-proof as the 7 Nm.

Blending longer FL or otherwise higher resolution data is not too difficult, much as I'd like to pretend that only by visiting me could you acquire this arcane skill!  :grin:  Registar does the sums for us. However, you cannot just drop in higher res data at a click. It needs to be done in Photoshop where you can feather it in gently and control the opacity of the application.

Thanks to all for the kind comments.

Olly

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ChrisLX200

ChrisLX200

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Get on with it Man! RGB is the stuff of life. Everything else is a game without rules...  :evil:

Olly

but.. but... there's no Green in it! Nor pretty Magenta stars!

Actually, I could really use your nice skies, I think I may have to visit - bring all my stuff then er., accidentally leave it there swtiched on and connected to your broadband :-)

Which begs a question actually, just how did you get broadband half way up a remote French mountain? I can't get a decent connection here in downtown Macclesfield...

ChrisH

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ollypenrice

ollypenrice

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but.. but... there's no Green in it! Nor pretty Magenta stars!

Actually, I could really use your nice skies, I think I may have to visit - bring all my stuff then er., accidentally leave it there swtiched on and connected to your broadband :-)

Which begs a question actually, just how did you get broadband half way up a remote French mountain? I can't get a decent connection here in downtown Macclesfield...

ChrisH

To my astonishment there was one broadband line still available in our village when I asked for one about ten years ago. I think that makes me and three others... It isn't a good BB conncection but it does work and we manage to run the four-scope robotic shed through it. We may still set up a satellite as well though. It's on the Robotic Shed Agenda, so to speak.

Olly

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Pompey Monkey

Pompey Monkey

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but.. but... there's no Green in it! Nor pretty Magenta stars!

Actually, I could really use your nice skies, I think I may have to visit - bring all my stuff then er., accidentally leave it there swtiched on and connected to your broadband :-)

Which begs a question actually, just how did you get broadband half way up a remote French mountain? I can't get a decent connection here in downtown Macclesfield...

ChrisH

Broadband? Just about. ;) Remote French mountain? Remote enough to be reet proper dark - the clouds (when you get them) really are black. Not yellow. Not even dark grey. Just black. It's quite surreal, and even a little bit freaky if you are used to urban skies! 

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