The Horsehead Nebula with new 12.5"

[SkyViking]

Hi All,
Here is the first serious test of the new 12.5" f/4 Serrurier Truss Newtonian after I got everything fine tuned: A quick shot of the famous Horsehead Nebula in Orion.
Please note that this is straight out of the camera, no processing was done apart from a simple curve stretch to reveal the dynamic range.

Link to full resolution image (3.6MB) (http://rolfolsenastrophotography.smugmug.c om/Astrophotography/Nebulae/i-szHrPtx/O)

Image details:
Date: 7th December 2013
Exposure: Luminance 35 mins @ -25C
Telescope: 12.5" f/4 Serrurier Truss Newtonian
Camera: QSI 683wsg with Lodestar guider
Filters: Astrodon LRGB E-Series Gen 2
Taken from my observatory in Auckland, New Zealand

This was taken in between clouds on a humid night with rather poor seeing and so I only managed 35 minutes of data.
I used a new coma corrector, the Baader MPCC MkIII. It seems to be very efficient at removing coma in the image; Stars are round and sharp across the frame from edge to edge.
I also installed the Ovision worm upgrade kit for the Losmandy G-11 mount, and as a result there is no star trailing in R.A. The performance of the mount is much improved, way better than I expected.

Overall I think this new scope is far superior to my old one and I'm very happy to see the flat corrected field produced by the new MPCC, and the top performance of the Ovision upgrade.
The light gathering power is obviously much greater too, probably about twice that of the old 10", given the increased aperture and fresh mirror coatings.

Comments most welcome.

Regards,
Rolf

[strongmanmike]

Yes, looking good.....

:thumbsup:

[Stevec35]

Yes I would be well happy with that Rolf. Looking forward to you really putting it through its paces.

Cheers

Steve

[gregbradley]

That's a great shot. Very similar to my TEC180 fluorite image in detail.

Greg.

[RickS]

Looks very promising, Rolf!

[SkyViking]

Thanks gentlemen, there might be some clear skies later this week - fingers crossed!

FWHM was around 3", a little on the high side for me. I have seen it much lower with the new scope on several other nights, so there is potential for much improved resolution here. :D

[TimberLand]

Looks great to me Rolf, nice original diffraction spikes too.

It is a real pleasure to photograph the night sky and even more so knowing you have built the gear that makes it possible.

Great scope, and good to see someone else getting good results with the Baader coma corrector, what back focus distance do you have behind it to the camera.

Justin.

[SkyViking]

Thank you Justin, I'm glad you like the scope :) The appearence of the spikes are a direct result of the guitar strings that I use for the secondary holder. This makes them long and thin and only visible on the very brightest stars.

I also find it interesting that the only hint of Alnitak is the long spike going across the frame from left to right. There is no visible light from it otherwise, even though it lies just outside the FOV. I attribute this to the Royce mirror's high precision surface which in theory should increase contrast. It seems like it does, although I only have this one image to analyse so far.

[multiweb]

Very neat Rolf. Can't wait to see some color with the new scope. :thumbsup:

[SkyViking]

Thanks Marc, I'm working on it :) I got a whopping 7 more frames in between clouds the other night :lol:
I spent yesterday creating new dark library and taking flats.:thumbsup:

[strongmanmike]

Good boy :)...actually I just got new bigger filters so I will have to...ah wait, no I won't, I don't use darks and hopefully no vignetting now so I won't need flats either :D ;)...

Always do flats!...bah :lol:

[SkyViking]

Hehe Mike, so your setup is completely dust and vignette free and your camera has no dark current, bias etc.?
How do you handle the natural vignetting?

Evidently your new cam produces great images, but with full calibration you can probably squeeze even more from it. Apart from the initial hassle of creating calibration frames is rhere a reason why you wouldn't try?

[Ross G]

Excellent quality Rolf.

Good luck with the new telescope.

Ross.

[SkyViking]

Thank you Ross, I'm looking forward to give it a whirl :)

[astronobob]

Im not and prob wont get to this calibre of imaging Rolf, but this looks real promising - looking forward to some imaging runs from you :thumbsup: