sharper Crux widefield - astro-trac

[Rigel003]

I had the opportunity to image the same field a few days later under cloud free skies. Much sharper, although the main constellation stars are less obvious. Bigger version with lots to look at here (http://www.pbase.com/rigel003/image/162332263/original). Dark streaks throughout, lambda Centauri nebula at top and Dark Doodad and globular NGC4372 at right.

I might have gone to town a bit with the saturation. Can't resist the impulse to improve on nature.

Canon 6D
70-200 f/2.8L lens at 100mm f/3.5
ISO 1600
single 3 minute exposure with Astro-Trac.

[Atmos]

For a single exposure that is looking pretty damn good so far :) It looks much nicer than mine but that was also at ISO6400 and 30s, there was 120 of them though! Still, yours wins :)

[Rigel003]

Thanks Colin. I tried stacking but it ended up less sharp than the single exposures. I think the software had trouble accurately registering all those gazillions of stars perfectly. Not sure that stacking lots of subs is so useful in a field like this anyway. It's very bright and there's not too much noise.

[bimberi]

Wow, 3 minutes and you got all of that! I'll have to try it myself now, hopefully the old 5D can stand up to the task.

[gregbradley]

That's a fantastic widefield.

Greg.

[Peter.M]

look at that chicken run! Sorry I couldnt make it down with you guys!

[h0ughy]

wow you have really nailed the use of the astrotrac - superb image

[Wodnas]

Terrific photo, well done. I am in the process of getting familiar with my new
Astrotrac.
Can you please share your method of good polar alignment.
Polar scope is hard for me as I don't have a clear view of SCP from home.
I have built a V align switch but east and west horizons are also restricted.
Might have to move.
Many thanks Bob

[Rigel003]

Thanks for the comments everyone.

Peter, I'll look forward to catching you next time. Never have been able to see a chicken in that.

Bob, I'm still finding my way with the Astro-trac. The polar scope on mine was next to useless, optically and mechanically, so I replaced it with a Polarie polar scope and then added an aftermarket SkyWatcher illuminator which fits it well. I point the pier to true south using iphone apps, then mount the camera and check elevation with a digital inclinometer. That usually puts me close enough to see the Octans trapezium asterism in the polarscope, or even disregard the polar scope entirely and get reasonable results in 2 min exposures. Haven't tried any drifting techniques. For this image, I connected it up to my laptop and used Backyard EOS to manage the exposures. Apart from other things, it makes focusing accurately easier than just using live view on the back of your camera. I'd be interested to hear about your V align techniques.

[Wodnas]

Thanks for the reply. The Astrotrac is new to me also. I'm doing similar without the polar scope but using BYEOS. Just starting to drift align but clouds have beaten me lately. A couple of links below about the V Align drift method. Looked like a good idea.

https://www.flickr.com/photos/wilsonp195/9672909390

http://www.cloudynights.com/page/articles/cat/articles/darv-drift-alignment-by-robert-vice-r2760

Cheers Bob

[RickS]

Really nice, Graeme!