Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: MarkS on Mar 17, 2014, 00:02:01

Title: Jupiter 16 March (Double Shadow Transit)
Post by: MarkS on Mar 17, 2014, 00:02:01
Taken around 10:50pm on Sun 16 March.
IS DBK 21 on Celestron C11 with 2x Barlow
500 frames at 1/30sec stacked in AutoStakkert and post processed in Registax
The shadows are of Io and Ganymede.

(http://www.markshelley.co.uk/Astronomy/2014/jupiterdoubleshadow16032014.jpg)


Here's one from earlier in the evening just after Ganymede had passed in front and before its shadow was cast on Jupiter:

(http://www.markshelley.co.uk/Astronomy/2014/jupitergany16032014.jpg)


Mark
Title: Re: Jupiter 16 March (Double Shadow Transit)
Post by: Tony G on Mar 17, 2014, 07:20:50
Mark

I was wondering if you managed to get these last night. Great images, well done.

Tony G
Title: Re: Jupiter 16 March (Double Shadow Transit)
Post by: mickw on Mar 17, 2014, 07:59:10
Very nice Mark well done
Title: Re: Jupiter 16 March (Double Shadow Transit)
Post by: Ivor on Mar 17, 2014, 10:18:41
Good effort, gald to see the wind was better on Sunday night.
Title: Re: Jupiter 16 March (Double Shadow Transit)
Post by: MarkS on Mar 17, 2014, 10:48:11
Quote from: Ivor
Good effort, gald to see the wind was better on Sunday night.

Guiding was much better than Saturday.  I was getting 0.4arcsec RMS for long periods on my belt drive EQ6.  It occasionally went above 0.5 RMS.  The type of the seeing conditions helped.  It was the high speed "jittery" kind of seeing instead of the "slow wave".  Guiding works much better with the former.
Title: Re: Jupiter 16 March (Double Shadow Transit)
Post by: JohnP on Mar 17, 2014, 13:45:12
Very nice indeed Mark - looks spot on to me. You did well... John
Title: Re: Jupiter 16 March (Double Shadow Transit)
Post by: Carole on Mar 17, 2014, 17:03:44
I particularly like the one with the red spot.

Carole
Title: Re: Jupiter 16 March (Double Shadow Transit)
Post by: julian on Mar 17, 2014, 19:04:06
Very nice Mark
Title: Re: Jupiter 16 March (Double Shadow Transit)
Post by: Mike on Mar 17, 2014, 19:05:08
Really nice that.
Title: Re: Jupiter 16 March (Double Shadow Transit)
Post by: Mac on Mar 18, 2014, 17:08:13
Very nice,

Mac.
Title: Re: Jupiter 16 March (Double Shadow Transit)
Post by: Fay on Mar 18, 2014, 18:23:58
Nice Mark. i did do one, with only one moon,  myself but looks a bit tatty. scope not big enough!!!!!!
Title: Re: Jupiter 16 March (Double Shadow Transit)
Post by: mickw on Mar 18, 2014, 18:25:32
Quotescope not big enough

But I thought size didn't matter  :oops:
Title: Re: Jupiter 16 March (Double Shadow Transit)
Post by: Fay on Mar 18, 2014, 18:26:40
it does in a lot of matters Mick ;)
Title: Re: Jupiter 16 March (Double Shadow Transit)
Post by: MarkS on Mar 21, 2014, 01:37:22
I've managed to tease just a bit more detail out of the Jupiter/Ganymede image by using 2500 frames instead of 500.  Here they are side by side:

(http://www.markshelley.co.uk/Astronomy/2014/jupitergany16032014.jpg)(http://www.markshelley.co.uk/Astronomy/2014/jupgany16032014v3.jpg)
Title: Re: Jupiter 16 March (Double Shadow Transit)
Post by: Carole on Mar 21, 2014, 07:48:17
Certainly a lot more detail Mark, was definitely worth doing.  Looks like a bit of detail showing on Ganymede.

Carole

Title: Re: Jupiter 16 March (Double Shadow Transit)
Post by: MarkS on Mar 21, 2014, 10:16:01
Quote from: Carole
Looks like a bit of detail showing on Ganymede.

Yes, the dark and light areas on Ganymede are just beginning to show now and they're genuine.  I've compared with similar images from folk who did much better than me on the same night.
Title: Re: Jupiter 16 March (Double Shadow Transit)
Post by: JohnP on Mar 21, 2014, 13:25:21
looks excellent Mark... Can you get rid of the ring artifacts down the RHS & I'd give it 10/10.... John
Title: Re: Jupiter 16 March (Double Shadow Transit)
Post by: MarkS on Mar 21, 2014, 14:43:30
Quote from: JohnP
looks excellent Mark... Can you get rid of the ring artifacts down the RHS & I'd give it 10/10.... John

Those ring (or bacon rind) artifacts are a common problem.  I think they are an artifact of the wavelets rather than a misregistration of video frames (we had the same discussion on Fay's recent image).  Lots of Jupiter images have them and others have edges very obviously blurred, which also looks really wrong.

I think the solution may be to produce 2 images:  one where wavelet decon is applied just up the point where the bacon rind has not yet started to appear and then another image where "full strength" wavelets is applied but which has bacon rind.  The two images can then be judiciously layered together to obtain the best of both.

Then you can give me 10/10 ;)
Title: Re: Jupiter 16 March (Double Shadow Transit)
Post by: MarkS on Mar 21, 2014, 20:16:39
For John's benefit then, here is the final version on the right (or underneath), without bacon rind.

(http://www.markshelley.co.uk/Astronomy/2014/jupgany16032014v3.jpg)(http://www.markshelley.co.uk/Astronomy/2014/jupgany16032014v4.jpg)

Nearly as many sequels as Rocky!

Mark