Witch Head Nebula IC2118 -Eridanus

[starfinder]

Hi All. Here's one I collected at the VicSouth Star Party last month. It's 5 hours of data (LRGB 150:50:50:50) through a Takahashi TOA130/EM-200 combination and SBIG STL11000M camera. Processed in CCDStack and Photoshop CS5.

I'm learning all the time about subtleties of image processing and there's much yet to learn. I couldn't process the faint parts without burning out the cores of the brightest stars. There are hints of emission nebulosity in the field and the blue illumination at lower right is from Rigel.

Suggestions and comments welcomed.

A larger version is at http://www.russellsastronomy.com/sky/Narrow%20Field/Hi-res/witch%20head.htm

Russell

[zipdrive]

That looks fantastic!

[marc4darkskies]

That's a very fine image Russell!! Nicely processed too. Well done!

The simplest way to process everything except stars is (in CS5) to Select->Color Range and then select the cores of a number of stars from bright to dim (use the shift key to add-select). Adjust the fuzziness to taste and hit OK. Then, from the adjustment pane, add a curves layer. It will automatically create a layer with a layer mask that shows only the stars. Click on the layer mask and from the masks pane, press Invert. You can now adjust curves without affecting stars. You may need to blur the layer mask to avoid sharp outlines or halos around stars. You can also Alt->Select the Layer mask itself and operate on it with curves to increase or decrease contrast. And don't forget the Shadow /Highlights tool (using the same layer mask).

Cheers, Marcus

[Martin Pugh]

Very well done Russ. This has to be my favourite nebula. The colours are great in this.

I am shooting this myself, but its very low for me and passes between 2 trees, so I get about an hour a night - when its clear.

At this rate it will take me 3 years.

cheers
Martin

[John Hothersall]

Don't see this dim big nebula often but this is an excellent result with solid detailed structure. Finer points of processing will come with time but this image is great.

John.

[Craig_L]

Great image Ross. Subtle details and colours. Only suggestion is to rotate it 90 degrees counter clockwise so we can recognise the old hag.

[strongmanmike]

Yeh Russ this is pretty good, it's a great looking nebula and not imaged all that much really, nice work, I like the colour variations you have revealed.

Mike

[starfinder]

Many thanks for the helpful comments and advice.

To all, a merry Christmas and clearest of skies in 2011.



Marcus, thank you for the useful advice and clearly described method. I've given it a try and it works fine for me. Yahooooo! That's another valuable tool to add to my already, full to overflowing, toolbox! I really need to get a bigger one!



Thanks, Martin. Subtlety of colour was one of my key objectives for this one. No, it's not easy being an astrophotographer - rotating Earth, turbulent atmosphere, terrestrial obstructions - all conspire against us. For things that we can control, those trees will just have to go! You'll get your prized image eventually and I look forward to seeing it in the fullness of time.



Thanks Mike. Subtlety in detail and colour haven't been my strong points in the past, but I'm working on them. So much to do and so little time!



Good suggestion, Craig. Will do!



Cheers John. It's been quite daunting for me to look at a raw image and consider what aspects I want to highlight. Detail and subtlety of colour were my objectives for this one and thanks for your comments.



Thank you zipdrive. I'm very pleased with the result, too!

[Alchemy]

Nice work, star colors show up nicely and the framing/composition is a winner as well. It's an item not on the dozen or so that continually get recycled, so thumbs up .

[Hagar]

Great result Russell, I tried this one last year and had some real problems getting the colours correct.

Well done

[starfinder]

Happy New Year to everyone and the clearest of skies wherever you observe :thumbsup:.

I've incorporated your comments and suggestions - many thanks - changing orientation to portrait and giving special attention to maintaining colour in the cores of the brightest stars. Modified image has been uploaded to:

http://www.russellsastronomy.com/sky/Narrow%20Field/Hi-res/witch%20head-portrait.htm

Russell :)



Thanks Hagar. Colours and colour balance can certainly be problematic. I chose an area of sky upper right for balancing background colour and applied a little bit of colour balance in CS5 to remove a slight greenish cast in the highlights and midtones. The results, though, can be very much "in the eye of the beholder".



Cheers Alchemy. Nice comment, thanks. It's quite challenging to present a subject that's a little bit different!

[TrevorW]

Great effort Russ, if you have GradX apply a coarse low aggressive to balance the background a bit to take out the glow from Rigel

[strongmanmike]

No way, that makes the image in my opinion :thumbsup:

[luigi]

Fantastic image Russell, color is truly spectacular and the glow gives the photo a magic touch.
Hang it on a nice wall!

[TrevorW]

Each to there own :P

PS: he did ask for suggestions, not ??

[Astroman]

Awesome image, very well processed. Can see lots of detail as well at background objects also..

[richardo]

Hi Russ, great image of this very faint and very wide object.
What struck me first when I viewed the large version from your site was its orientation.
I thought great, not like every one elses who've taken this object. It makes you look for the face more and in doing so draws attention to the faint wisps of reflection (love reflection), then I noticed the face was looking at the glow- being Rigel.. perfect!
Love the soft intricate colours, it really is what this nebula is about because it's sooo faint.

In my own opinion, for ascetics, artistic framing and license, keep to the original posted.
I don't know if you took any flats or not, but if you are thinking there is a gradient, take some flats for peace of mind if you haven't already.
Other wise I think it's great as is!

Rich

[marco]

Hi Russ, very nice image of one of my favorites objects, well done :thumbsup:

Clear Skies
Marco

[multiweb]

Great shot. Nicely done. :thumbsup:

[CoolhandJo]

Nice one! GReat detail focus and colours...

[strongmanmike]

Yeh he did and Russ should try what you say to have a look. I just recon the glow gives the image that mysterious quality and cleverly just suggests the illumination power of the mysterious obscured light source (ie Rigel).

Mike

[irwjager]

Very, very nice! We don't get treated to this one too often - thanks!

[starfinder]

A big thank you for your positive comments and suggestions. I feel like I'm finally coming to understand the ways to use the very wide range of tools available for astro-image processing :). I'm even using some of them for my terrestrial images too! Clear skies to all.













Thanks guys. Praise indeed :thumbsup:! I'm pleased to have added something a little different to these excellent forum pages. Clear skies.



:thanx: Richardo for taking the time to comment. Yes, I took flats, but I'm learning that getting good ones is one of the harder parts of this hobby! I, too, love the way the image comes together with all its subtle qualities, yet pleasing detail.









:help:Gentlemen! Gentlemen! Please go back to your corners! Shake hands and agree to differ!

You have both made valid and important points and thank you for them :thumbsup:. TrevorW, I'll try the gradiant removal and see how it looks. However, I agree with Mike that a strong feature of the image is the glow from Rigel appearing to illuminate the nebula - this is what actually happens in space - and it is pleasing to perceive this connection in the image.

[Paul Haese]

Very nice work Russell. Colours and stars are all superb.

[starfinder]

Many thanks, Paul. I'm very glad you liked it. :thumbsup: There were many facets to control in the processing of the image. Stars and colour were two of the most important for me. Clearest skies.