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View Full Version here: : Jupiter, Big Full Moon, Saturn 18th Feb UT

von Tom
19-02-2011, 12:52 PM
Hi All,

Jupiter, the Full Moon, and a sequence of Saturn last night.

Jupiter was 20 deg above the horizon and seeing was extremely poor, however I thought the action around the Great Red Spot was worth it. I know that Europa was transitting but I don't think any of the dark spots are shadows. I've shown the original stacked image and then 3 differently processed images.

The Moon was about 357,000km away last night, 1 day before perigee. It fills completely my DSLR field of view! Shown with colour saturation boosted. Single frame taken at midnight.

I shot Saturn between 11:30pm and 1am and was lucky to capture the complete transit of the "Dark Spot".

Thanks for looking,

Tom
AG Hybrid
19-02-2011, 02:03 PM
Nice work. The picture of the moon is very very good.
Derek Klepp
19-02-2011, 02:10 PM
Love that moon shot.How do you find the tracking with the Dob at high powers when doing the planetary shots?
Derek
Quark
19-02-2011, 05:42 PM
Nice work Tom, especially like your Moon image and Saturn.
A top effort for the equipment that you are using.

Regards
Trevor
michaellxv
19-02-2011, 06:00 PM
Nice work Tom. The moon shot is amazing with the colours you have pulled out of it.
Matt Wastell
19-02-2011, 09:23 PM
Thanks Tom - I do enjoy your Saturn shots and presentation - the storm looks awesome!
von Tom
19-02-2011, 11:10 PM
Thanks again for the comments.

Derek, the tracking with the 12" Dobsonian is OK for planets. Here's a video clip used to create one of those images in the Saturn pic (14:04UT):
http://www.youtube.com/watch?v=T_KHeyO_P24

The movement you see is typical of the tracking. About 60% of the time, at this magnification, I have to correct manually during the exposure (using "rate 2x"), and if I do that I have to anticipate for a very short moment of non-tracking before the tracking kicks back in (like a backlash of sorts).

Also, I have found that you need to wait a minute or so after slewing to an object before the tracking movements calm down into somethin more regular and accurate.

It's definitely not something you can set and forget, you need to keep an eye on it. The Jupiter image above was shot with no auto tracking but using manual alt/az movements of rate 1x.

Hope this helps.

Cheers,
Tom