NGC2736 - Pencil Nebula

[jase]

Hi,

...Still processing data from a few previous runs. I sat on this one for a while given Greg recently posted a great image on the target and I'm not one to show competing images. So, here's my rendition of the scene;

NGC2736 - Pencil Nebula (aka Herschel's Ray) (http://cosmicphotos.com/gallery/image.php?fld_image_id=206&fld_album_id=11)

Less than perfect data making gradients a tall order to deal with. Feels a little too turbulent for my tastes, but I was keen to avoid making it uber smooth like plastic. That said good detail was obtained in the Ha data set. No OIII acquired. The blue and green channels were relatively strong to begin with on the RGB combine, however to give them more punch I blended (Ha+L) in to green at 30% and blue at 20% which was selectively masked. Less than ideal, but worked out once channels were balanced. Apologies if this upsets the imaging purist, but in this instance it wasn't the journey, but the destination.

Enjoy! :)

Cheers

[strongmanmike]

Very nice work again Jase :thumbsup: It's a kinda quirky odd piece of nebulosity really but still, interesting.

Mike

[Octane]

Jase,

Beautiful, as always.

Although, I can't help but feel the composition is a little left heavy.

Minor criticism, though.

Looking forward to more.

H

[skeltz]

mmm...look s bloody good to me jase ....keep up the good work!

[jase]

Hey Mike, thanks! Certainly is an interesting neb, but really the whole Vela SNR complex is a gold field full of treasures. Difficult to say if the region is better suited to traditional RGB or narrowband imaging. Both work I guess. Thanks again.:)



Thanks H. :) Yes, I procrastinated over the framing. Guide star selection with the PIR was probably poor judgement on my part. I could rotate the image 90 CCW and call it the sling-shot nebula :P. I settled on this composition as I liken it to being similar to entrancing Veil nebula. So I'll call the composition, the southern witch's broom stick. :lol: All jokes aside, I do acknowledge your comment. The twists of neb in the lower left corner don't help with the weighting. It will have to do for now. Thanks for your constructive feedback.:thumbsup:



Thanks Rob! Haven't seen you around the traps for a while (neither have I been however). Hope you've still got the Titan. Thanks for your comments. :)

[skeltz]

no probs bro good too see you!

[Martin Pugh]

Very nicely rendered Jase.

take care
Martin

[spearo]

Looks great
I have yet to learn how to mix and blend all these channels!
so much to learn...so little clear sky time...
frank

[avandonk]

Looks alright to me Jase.

Here is an animated GIF of your red channel with my image in HA. 2MB

http://d1355990.i49.quadrahosting.com.au/2010_03/jgif.gif

I made it high res so the 16" RCOS was not disadvantaged.

We are comparing 300 mm APO lens to 3360 mm RCOS.

Bert

[gregbradley]

Wow, that is just sensational. I love it.:eyepop:

Perfect framing and colour, lots of detail and that nice little jellyfish style neb in the bottom right. Gorgeous.

Where is the 16 inch RCOS located? Gee they are good scopes.

Greg.

[marc4darkskies]

Hey Jase - very nice mate, as always! :thumbsup::thumbsup:

I wouldn't call myself a purist, but blending Ha with blue & green? ... I dunno :question: :rolleyes: .

Cheers, Marcus

[multiweb]

Beautiful rendition - top work as usual. :thumbsup:

[gbeal]

Lovely shot Jase. I have about 2 hours of Ha and O3 and was quite happy with my meagre efforts, until I saw this.
Gary

[CoolhandJo]

Top work... again :)

[telecasterguru]

Beautiful image.

Frank

[AlexN]

Lovely... One of my favorite areas of Vela..

[Paul Haese]

Nice going Jase, some of the gradient work is just ever so slightly visible; but this is certainly a lovely image. Wish I could do the same.

[Peter Ward]

Jase, a wonderful renditon of a tough object.

Excellent acquisition and processing.....Great scale (16"RCOS Hummm....)

Top shelf to be sure! :)

[jase]

Cheers Martin! Thanks for checking it out. :)



One word Frank - experiment. If you play it by the book all the time, you will not develop the skills. I hear you on the clear sky time. I'm using gear all over the place, not just mine so at present I've got more data than time to process. It doesn't rain, it pours. Next few months I'll probably release nothing...who knows!:) Looking forward to seeing your results of the CCD imaging journey...Thanks for taking the time to check out the image and make comment.



Thanks Bert. :) I like your comparison. 300mm lens packs some punch thats for sure. I was admiring you Eta mosaic the other day. May use it for a scaffold image in due time.



Cheers Greg. :) I liked your rendition too, despite the thread going slightly off track. The 16" RC is located in Victoria.



Ummm... you're a purist Marcus. :lol: You're in denial or something ;) Seriously, you're only limited by your imagination and skills. As I've already mentioned, if you play it by the book all the time, I don't see the value. You should try it sometime. Thanks for checking it out. :)



Thanks Marc. Appreciated. :)



Hey Gary...must of sparked interested to get a comment from you. ;) Only kidding mate. Seriously, post your image. Every image portrays the scene differently so deserves it own time in the spot light. Pleased you liked my rendition and thanks for making a comment. :)



Thanks Paul. Pleased you liked it.:thumbsup:



Cheers Frank! :)



Thanks Alex! :) I could agree more. It certainly is a special area for imaging. Thanks for you comment.



Cheers Paul. :) Yes, as I mentioned I feel the background is turbulent. I can image lower than 50 degrees in the east with this rig as the gradients get too nasty. I'm use to dealing with them, but these took nearly all the tricks out of the bag. Lets just say GradientXterminator couldn't tame them, resulting in manual extraction using masks.:confused2:



Thanks Peter. Its not an easy target, but I'm pleased with the result none the less. Pleased you enjoyed it too! :)

====

Thanks again all for your support. Appreciated. :D

[avandonk]

Thanks Bert. :) I like your comparison. 300mm lens packs some punch thats for sure. I was admiring you Eta mosaic the other day. May use it for a scaffold image in due time.

I might start up a new business 'scaffolding for the gentry'. Just kidding.

Anytime anyone needs an almost perfectly rectilinear image as a scaffold for a mosaic with longer length optics just ask.

We are all doing battle with the limitations of our hardware. Collaboration is one way to win.

Actually Jase the 300mm Canon F2.8L is really a 290mm focal length lens. That way they can crib a bit to call it f/2.8 with a clear aperture of 104mm. To be f/2.8 at 300mm the clear aperture would be 107mm. The real limiting factor and expense is the single crystal of Magnesium Fluoride that is the heart of this lens. This single crystal element is in an 'o' ring sealed nitrogen atmosphere. There are also two ED elements in the main front lens combination. The front element is an optical flat which can be easily replaced if damaged.

I have had this lens out in the worst conditions for many years and it still performs like new. It is fully sealed against dust and moisture!

Sorry about the rant. Imagine how long the rant would be if I had a 16" RCOS!

Bert

[jase]

No problems Bert. At a glance, your Eta mosaic which I believe was two panels, I can match with 6 panels using the FSQ and 16803 chip of the Apogee U16M. Obviously, I'll have a little more resolution on my side operating at 530mm compared to 300mm (or 290mm as you suggest). Will see how things progress...no promises!:)

[RobF]

Fascinating object Jase, thanks for showing.
Its looks like special effects from Star Trek to me - one of the more recent series that is - not TOS ;)

[avandonk]

Jase I calibrated an image taken with the 300mm lens to a sky map with RegiStar. The number came out to be 292mm.

You utter utter B. making a better mosaic!

Bert

[DavidU]

Bert, are you sure the element in the lens group is Magnesium Fluoride ?
Unusual choice for visual work I think.

[avandonk]

Yes it is a single crystal of Magnesium Flouride 107 mm in diameter. It is easy to test this. Just shine a green laser pointer down the lens and the scatter from the laser beam disappears completely as it goes through the MgFl. There are no impurities or refractive anomalies to scatter the light. MgFl is isotropic if that fact helps.

FPL 51 and 53 glass is a mixture of MgFl and glass. I will leave it to you to work out what is better. Low spectral dispersion is the game.

Bert

[Tom Davis]

Excellent! So pretty!!

Tom

[Ric]

Fantastic capture Jase. the filaments look great winding their way through space.

A fine job indeed.

[jase]

Thanks Tom. Pleased you liked it. :)



Cheers Ric. Seems to be a target well suited to long focal lengths. Thanks for your comments. :)


:D

[Garyh]

Beautiful detail Jase!
Might give this ago tonight..
Lookin good outside! :)

[DavidU]

I see, that would be one expensive element ! I just found it odd they would use MgFl ( transition .12um - 8um) in a visual.The lens must be superb.