Angry star....

[Peter Ward]

Unfortunately mother nature has given Sydney very few clear nights of late, so it is a case of grab what you can...

This is more a proof of concept image that I used to test my system at around 3700 mm focal length.
Why? As Fred says "narrow field rules!"

Despite the eggy edge stars (need to use a different barlow) and slightly soft image (a steady atmosphere at these FL's is very critical) I don't think the result was too tragic.

http://www.atscope.com.au/BRO/gallery37.html

[RB]

Looks great to me Peter, nice colour, lovely detail and image scale is fantastic.

:thumbsup:

[bluescope]

Nice close up Peter !

:thumbsup:

[Peter Ward]

Thanks RB, Bluey.... :)

I forgot to mention the data was captured with a first quarter moon in the sky... hardly a problem given the brightness of the subject matter.

AND a correction....according to The Sky's image link, the working focal length was 5300mm (!!)

[Kevnool]

Great close up Peter, One could get lost peering into it.....cheers Kev.

[Garyh]

Nicely resolved Peter. That old fickle finger stands out very nicely.
Beaut closeup!

[h0ughy]

pleasurable to the optic nerve, love the detail Peter

[Peter Ward]

Thanks Dave, Kev, Gary.

Eta itself is quite a challenge....I'll be keeping fickled fingers crossed that it remains clear tonight so I can get some HDR and high res data of Eta to layer with the rest.....

[Ric]

Lovely closeup of the Keyhole Peter, there's a lot of great detail to see in there.

[strongmanmike]

Even though once again you haven't given us the best view ala a small file :doh: :scared:... this is clearly a lovely subtle image Peter, the extra FL certainly helps in revealing the fine detail. It's still not quuuuuite what I would call exemplary data for such a high end outfit but it is pretty good plus as you say seeing is an important factor.

When/if you've done more high res data it'd be interesting to see how your fickle finger stands up in this lineup, it would be a nice clear test of your superb outfit and the new configuration I recon..?

http://www.pbase.com/strongmanmike2002/image/109153793/original

Hopefully you would display the full res then? :rolleyes:

Mike

[Peter Ward]

IMHO high res deep sky imaging requires superb seeing and great guiding, as the latter literally swamps the optical resolution of most systems.

I typically get 3-4 arc sec seeing....which is around 10x worse than the resolution of a diffraction limited 360mm aperture scope.....(and 5x for a 150mm).

Hence lining up multiple fickle fingers does not say much about a systems intrinsic resolution....to me at least...but says buckets about the seeing on the night.

Not its not exemplary data, but for 50 minutes under a 1st quarter moon from the 'burbs.... I can live with it ;)

[strongmanmike]

Burk, burk, burk...chicken! :lol:



Moon and burbs have little effect on resolution :shrug:.. but yes still pretty incredible to think about considering what was considered do-able years ago..

Mike

[rat156]

Hi Peter,

I reckon that this is great, considering the focal length involved. But I have one minor nitpick, green stars???

Is this an effect of the atmospheric scattering, whereby the red channel is intrinsically sharper than the other two?

What length are your subs?

Cheers
Stuart

[Peter Ward]

I've added a hyper link hotspot over the "celestial finger" that will take you to a high res crop of the same.

For those who want to get straight to it,the direct link is here

http://www.atscope.com.au/BRO/gallery37a.html

[Peter Ward]

Must be my canine colour vision :) , but I can't see any green stars on the monitor I am using.

10 minute subs....but I suspect 5 mins may have been better for high res.

[strongmanmike]

That's excellent Peter, wish you would just post high res data in the first place, you have such an excellent system it is a shame you feel it too risky displaying it's full capabilities..:shrug:

Nice job

Mike

[rat156]

Hi Peter,

Photoshop is your friend.

Here's a crop of one of the stars in your picture with the colour picker tool set to point source. Unfortunately the cursor didn't show on the screen grab so you'll just have to believe me that it's on the lower part of the green star to the left of the dialogue box.

Cheers
Stuart

[spearo]

Very nice Peter!
Love the resolution and colors!
frank

[Peter Ward]

And so it is! Sort of a yellowy green....which are indeed verboten! :)

Now fixed

[multiweb]

Wow! That's awesome. :eyepop: You can even make up the Homunculus. Top work and unbelievable tracking. :thumbsup:

[Quark]

Lovely image of an incredible object Peter,

Love the subtleties of the colours and most delicate structure within this image. Is it my imagination or can I see a hint of the Homunculus under the vertical diffraction spike of Eta Carina?

Well done
Regards
Trevor

[Peter Ward]

Thanks Trev! :)

You have a keen eye! ...there is indeed a very short RGB sub exposure layered in of the Homunculus....the brightness of which is proving difficult for yours truly to tame without it looking artificial.

(I suspect a 24bit CCD might be required to capture the full dynamic range of this delightful region)

[Peter Ward]

For those that like the technicolor look....a high saturation version here

http://www.atscope.com.au/BRO/gallery37c.html

[Jen]

:eyepop: very nice Peter :thumbsup::thumbsup::thumbsup:

[AlexN]

Narrowfield does rule! I like the shot, would love to see it in higher resolution...

[Peter Ward]

Thanks Jen, Alex. The original was taken at 2x bin i.e. about 2000 pixels across (1x seemed is overkill for a FL of 5000+ mm) I'm afraid you'll have to be content with 70% res for now.

Judging by the number if views this image has received, I guess narrow field is popular :)

[AlexN]

Many people love looking at narrow field.. Not many attempt it... True enough, bin1x1 would have definitely been overkill at that focal length... resolution would have been awesome though!! :) Did you use AO? I would have thought it necessary at such a focal length..

[Bassnut]

mmm, 5300mm FL, yummy, and very smick Peter, tight as. Slightly duochromic, but top guiding (natch, but wouldnt even try this without a PME), bin 2 is appropriate and works well. So that was F12?, what times barlow was that then?.

[Peter Ward]

While I am an advocate for oversampling, 1x1 binning simply would have lowered the system gain with *no improvement in image resolution* at that focal length (there are books written about Nyquist sampling, so I won't dwell on this here).

But sure, had the seeing been great, a 1x1 bin would have paid dividends.

I did indeed use an AOL for the luminance data (...despite the naysayers...guiding at 10Hz is so cool...) but the RGB required 0.5 sec guiding so wasn't used for that part of the data.

Cheers
Peter

[jase]

Was horrified to see such short integrated exposure time, but then realised the data was binned.:lol: I concur, probably gave you optimal sampling given environmental limitations. Lovely work Peter.:thumbsup:

...mmmm, o v e r s a m p l e d d a t a ....<drool>
....mmmm d e c o n v o l u t i o n...mmmm

a match made in heaven...until you need to deal with blooms...eeeekkkkkk arrrrrgggggg.

[Peter Ward]

I tried two...the result posted was with an AP 2". My Baader FFC gave better edge results, but was hovering around the 7000mm mark....but on a good night, might prove to be awesome ;)

[Peter Ward]

and a tip 'o the hat to you Jase :)

[pgc hunter]

I love it, very asthetic. Nice job capturing the rude finger :lol:

[atalas]

Excellent Peter!