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JohnH
07-07-2006, 08:35 AM
Have been unable to image for a while due to probs with the mount and then a family issue. Half a moon in the sky messing things up a little but I had a go at M8. Here is the result. Combination of 8*2 min shots at iso 1600, processed with IP.

Dennis
07-07-2006, 09:53 AM
Looks very nice John. I like how the dark lanes are nicely visible, along with the diffraction spikes on the brighter stars.

Cheers

Dennis

RB
07-07-2006, 10:00 AM
John that is Beautiful !!!
I love how the outer red nebulosity looks like velvet.
And like Dennis said the diffraction spikes look awesome.

I assume you used the Vixen and the 20D.
Very nice combo.

Excellent processing too.
Well done.

JohnH
07-07-2006, 10:28 AM
Yes, that was the 20D (unmodded) at prime of the VC200L (f9). Had to reduce scale a lot to fit under the 150k limit...

avandonk
07-07-2006, 11:22 AM
Shows very nice detail. Excuse my ignorance but what type of scope is it? Tracking is also superb.

Bert

JohnH
07-07-2006, 11:57 AM
Bert,

The VC200L is a variation on the Dall-Kirkham design - corrector is combined with the sperical secondary, the other oddities about this tube are a non-spherical primary formed by the coating process and a built in corrector/flattener (in the draw tube). Basically the scope is optimised for imaging and has a very flat field (attached is a corner crop of the full frame lagoon image fyi). More info here:

http://www.vixenamerica.com/Products/Default.asp?TopCatCode=TS&Fam_or_Cat=VC200L

tornado33
07-07-2006, 01:02 PM
Thats a very good image, I notice particularily the subtle changes in colour of the nebulosity shading from pink to blue.
Scott

Lester
07-07-2006, 01:09 PM
Hi John,

Like your image and the infomation on the Vixen. I didn't realise it was a scope with such potential.

Dennis
07-07-2006, 01:13 PM
A fellow IIS member, Dave Larkin also has a VC200L, and he recently told me that a friend of his who also has a VC200L had the mirror recoated at a reputable place in Australia. To his consternation, his VC200L will not longer come to a clean focus.

This would corroborate that the final aluminising/coating process actually contributes a unique shape to the mirror surface, so it would appear that VC200L mirrors need to be returned to Vixen for recoating?

Cheers

Dennis

Lester
07-07-2006, 01:24 PM
Gosh! Dennis,

there always seems to be a catch. Never heard of such a thing before. Wouldn't think an aluminised coating could alter the curve of the surface, because it is supposed to be uniform right accross the mirror. I will watch this space for any follow up.

Striker
07-07-2006, 01:33 PM
Thats a great result John..well done

Itchy
07-07-2006, 02:13 PM
That is a nice shot John.:thumbsup: :thumbsup:

Allthough well processed, it is possible to lift it a little more. This is often a personal preference. I have tweaked the jpg a little with curves to increase contrast. I hope you don't mind.

Cheers

JohnH
07-07-2006, 02:18 PM
This is 100% accurate, due to the "Vixen Sixth-Order Aspheric Cassegrain" design, I assume by sixth order they refere to the degree of fit to a hyperbolic mirror, in any case a Vixen re-cost does not cost much more than an onshore job as I understand it, of course there is a shipping delay to take into account...I don't see that as a problem though - re-coating is not a regular occurance. Hope your friend's scope is back in service now....

JohnH
07-07-2006, 02:28 PM
I LOVE it when I get feedback - in fact I had a play with this during lunch - processing was a quickly done job last night an I realised I had more details in I may have pushed too hard with my second go at it...