Keyhole in Hydrogen Alpha

[multiweb]

This is the last from my keyhole serie. I did some Ha as the moon was getting a lot brighter and the seeing wasn't too bad the first hal but somehow got really bad after a while so I had to throw the second half of the subs. About 1.5h worth out of 3h.

I used the Ha channel to blend details into my NIR version and also did a stand alone. Little noisy but still some cool details.

There's a HD version here (http://www.astropic.net/astro/keyhole_1800mm_ha_HD.jpg). [1.4MB]

I'm probably at the limit of that refactor but the exercise was a very good wake up call on the guiding side of things. Will try with larger aperture from now on, and the AO. :)

[jase]

Shame to throw data away Marc. I know the feeling, but I would say in this instance 'less is more'. A great result! Well done. :thumbsup:

[Merlin66]

Marc,
In the NIR composite, what's the diffraction patterns on the brighter stars???

[multiweb]

Scattering from the FFC. You can see the same effect on the Ha version. Fringes around Eta. My guess would be clips or spacers inside the barlow element. Still that's F/20.

[multiweb]

Thanks mate. :thumbsup: Yeah I always feel like it's a waste but I couldn't use any of them. The FWHM just doubled up in the space of 30min. Terrible. And I was still at the zenith.

[Ross G]

Great photos Marc,

I like the look of the colour photo, unique and pleasing.
Looking forward to seeing you try this technique on some other DSOs.

I love the monochrome Ha photo. Beautiful smooth tones and the long focal length has brought out some great detail.

Good luck.

Ross.

[RobF]

High class work as always Marc. Really pushing the gear and it was worth it.

[gregbradley]

Ah yes, a nice tight Ha from a good refractor, love it. Its super sharp. You did the right thing wasting the poor subs. Its all part of what it takes. Its hard but thats the way the imaging cookie crumbles!

Greg.

[Larryp]

Particularly love the colour version, Marc! Great work:thumbsup:

[RickS]

Good job, Marc! The NIR blend is very interesting.

[peter_4059]

Interesting stuff Marc. After multiple fails in recent imaging sessions I know how you feel about throwing away hours worth of data.

[SkyViking]

Very sharp details and great contrast in the Ha. The resolution is awesome, nice work Marc :) A pity that you had to waste some subs, but that's just how it is sometimes. The Ha is a great addition to the NIR in the colour image.

[multiweb]

Thanks Ross. :thumbsup: Now I have the guiding bits sorted out with the OAG I'm going to get the C11 out again for this. It should be more suited.


Thanks Rob. :thumbsup: Glad you liked the shots.


Thanks Greg. :thumbsup: Yeah I was pretty bummed out about losing half. Because my focus and guiding were spot on I was certain I had 3h of good stuff. It's only when I was flicking through the subs afterwards that I realised the last batch was pretty bad. Due to worsening seeing only. Just got worse. And Ha is not forgiving at that FL.


Thanks a lot Larry. :thumbsup:


Thanks Rick. :thumbsup: You should try it with your monster scope. :)


Thanks Peter. :thumbsup: Yeah it sucks.


Thanks Rolf. :thumbsup: Yeah I think it's a good way to boost the blues and details in the neb. Just 15% blend in the lum is enough. Punch all the stars out with a star mask from the Lum coz Ha doesn't have any stars anyway. Keep the sharp neb details only. Adds a bit of contrast and definition in the boring NIR background bits.

[David Fitz-Henr]

Nice work Marc; great details in that Ha version! :thumbsup:

[Peter Ward]

Some technical aspects I'd probably work on, but I have no experience of how commercial optics perform in NIR, so well done for pushing the envelope!

That said, having seen some trans-Tasman NIR trail-blazing, I really like your version.

Nicely captured. :thumbsup:

[allan gould]

Marc
Really innovative and I like the images as they have turned out well. Good to see something different down a well worn path. Congratulations.
Allan

[multiweb]

Thanks David. :thumbsup: Looking forwrad to the bunyip version.


Thanks Peter. As usual you don't miss a thing. :thumbsup:

I don't think the glass in IR is significantly different than other wavelengths TBH. It's the first time I've seen any diffractions from the FFC though.

Yeah I'm working on it actively: guiding and camera tilt. Back to the basics. The Ha processing could have been a little lighter handed as well. I got a LUM shot off the ESO and I really wanted to see how far I could dig mine before it looked silly. The rendition only looks half silly. ;)


Thanks a lot Allan. :thumbsup: The way I look at it there's always new stuff to get out of known targets. When we image a DSO every time we remember where the (only) guide star is (greatly helps with an OAG), we know the exposure times that work, we recognise smaller or fainter features and we can process accordingly. So if you know what to look for you get better at it and your pic is a little nicer than same time last year and you hang it up over the old one. It's all part of the fun.

[LucasB]

Fantastic shots Marc. Love the detail in the Ha and the colour rendition in the NIR is beautiful!:thumbsup:

Lucas

[multiweb]

Thanks Lucas. :thumbsup: I see you have FFC for sale. :)

[Alchemy]

Haven't done much astronomy for a while, but I still pop in for a look every now and then, your image caught my eye, this NIR produces some very interesting results, nice work Marc.

[multiweb]

Thanks Clive. :thumbsup: What have you been up to? Still got the obs?