Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: MarkS on Aug 23, 2008, 15:11:40

Title: Astro-Cows
Post by: MarkS on Aug 23, 2008, 15:11:40

Trying to teach French cows the finer details of astrophotography ...

(http://gallery.orpington-astronomy.org.uk/albums/userpics/10046/cow.jpg)
Title: Re: Astro-Cows
Post by: JohnP on Aug 23, 2008, 15:17:22
Is it a cow or a bull....? Either way I wouldn't go near it..... ! John
Title: Re: Astro-Cows
Post by: Mike on Aug 23, 2008, 15:45:28
What is that mount Mark?
Title: Re: Astro-Cows
Post by: RobertM on Aug 23, 2008, 15:54:24
Well if that's a bull then it probably won't be recognisable afterwards :(
Title: Re: Astro-Cows
Post by: MarkS on Aug 23, 2008, 16:22:13

The mount is the CG5 that came with the C11.

The bull is friendly (I hope!) because I feed him pieces of stale baguette.  The true test will be when I'm out there in the dark photographing the Milky Way.  I'll defend myself with a stale baguette!
Title: Re: Astro-Cows
Post by: Tony G on Aug 23, 2008, 16:47:55
Mark,

Be careful with the RED lights at night, as all the bull will see is total blackness with a glowing red target, (with you attached to the end of it)   :lol:

Tony G
Title: Re: Astro-Cows
Post by: MarkS on Aug 24, 2008, 10:56:45

After a whole afternoon of instruction, this is what the bull produced:

4 x 5min Nikon D70 at 18mm F4.5 ISO 400

(http://gallery.orpington-astronomy.org.uk/albums/userpics/10046/milkyway230808%7E0.jpg)

This will be improved once he learns to take flats ...

P.S. Someone forgot to turn the farmhouse lights out!  The red lights are from a telecom mast.  Jupiter is very bright. 
Title: Re: Astro-Cows
Post by: Carole on Aug 24, 2008, 11:43:32
Wow Mark, that's fabulous, and I believe this was one of Mike's challenges for the month.

That looks like it is a Bull as it has long hairy bits where the udders would be on a cow.  Unless the hairy bits are the end of it's tail.

I am currently in Devon staying with my Uncle and Aunt and I took my telescope but not my imaging kit as I am only here for a long weekend and thought it would be impolite to be outside for a whole evening.  They have fabulous views of the ecliptic and are on a hill so got a great viewing of Jupiter which they saw for the first time in their lives.  Unfortunately though they are alongside a busy road lower than they are so bright street lights were right in our faces, so imaging would have probably not been all that good anyway.

Carole

 
Title: Re: Astro-Cows
Post by: MarkS on Aug 24, 2008, 12:45:47

The astro-cow also had a go at Jupiter last night - 300 frames of 0.2 sec with an SPC900 webcam + barlow on the C11:

(http://gallery.orpington-astronomy.org.uk/albums/userpics/10046/jup23aug.jpg)
Title: Re: Astro-Cows
Post by: Tony G on Aug 24, 2008, 13:29:08
Mark,

Great images, well done.

Another note on the Cow/Bull, don't drink the milk until you find out. ;)

Tony G
Title: Re: Astro-Cows
Post by: Rocket Pooch on Aug 24, 2008, 13:43:58
Quote from: MarkS on Aug 24, 2008, 10:56:45

After a whole afternoon of instruction, this is what the bull produced:


Very Milky Way!
Title: Re: Astro-Cows
Post by: Fay on Aug 24, 2008, 19:55:22
Very nice Mark. Looks like a bullock to me.
Title: Re: Astro-Cows
Post by: MarkS on Sep 07, 2008, 22:22:14

Re-processed to subtract the background and thus bring out more detail.

4 x 5min Nikon D70 with 18mm lens at F3.5 ISO 400.

(http://gallery.orpington-astronomy.org.uk/albums/userpics/10046/mwayriberac.jpg)
Title: Re: Astro-Cows
Post by: MarkS on Sep 08, 2008, 01:10:19
I've also re-processed the Jupiter image from 23 August.  This time stacking the 80 sharpest frames instead of the 300 frames used previously.  Deconvolution was applied in both cases.

Previous image (using 300 frames):   
(http://gallery.orpington-astronomy.org.uk/albums/userpics/10046/jup23aug.jpg)

New image (using 80 frames):
(http://gallery.orpington-astronomy.org.uk/albums/userpics/10046/jup230808v2.jpg)

Christopher Go's images of 18 & 27 August make interesting comparisons: http://www.christone.net/astro/jupiter/
Title: Re: Astro-Cows
Post by: RobertM on Sep 08, 2008, 09:20:50
That looks really good Mark.  It certainly pays to be choosy - I had no idea how much difference that made.  Also that's a great widefield shot of the Milky way with Jupiter and nicely processed to subdue the light pollution.

Both are really excellent results.
Title: Re: Astro-Cows
Post by: Fay on Sep 08, 2008, 09:32:10
Yes, I thought that the more stacked subs the better, obviously best to be picky & only use the best one's.

Love the Milky Way, Mark.
Title: Re: Astro-Cows
Post by: JohnP on Sep 08, 2008, 10:27:38
Fay - doesn't make sense stacking frames if they are blurry.....!

That's excellent Mark - Certainly one of the best Jupiter image from an OAS member - Red spot is well defined & you can actually see detail in it also bands, spots & festoon's showing up nicely...

Well done - John
Title: Re: Astro-Cows
Post by: Tony G on Sep 08, 2008, 12:55:44
Mark,

Great images, especially the last Jupiter. I was under the same assumption as Fay, the more frames the better the image, but thinking about what you said John, it seems obvious now that if you keep stacking blurred images on top of each other it would be blurred.
I'm going back to a few of mine, and see what I maybe able to do. (if I get a chance).

Tony G
Title: Re: Astro-Cows
Post by: Fay on Sep 08, 2008, 13:10:11
Of course I would not stack blurry one's!
Title: Re: Astro-Cows
Post by: JohnP on Sep 08, 2008, 13:39:48
Fay as you know when stacking you get images that are very sharp (excellent moments of seeing) through to totally blurry (crap seeing) - obviously it's down to you to decide what % of the images are worth keeping/ stacking. I think Mark was just a bit more critical in which frames he stacked 2nd time around & it really improved the image...

John
Title: Re: Astro-Cows
Post by: MarkS on Sep 08, 2008, 13:53:01

Yes,  John is right, some frames are sharp and others are blurry - you need to decide what % of images to use. 

Now, in theory, Registax should be able to select those best frames using some kind of quality measure but I've never got it to work successfully for planetary images.  So I displayed the frame list and ticked the frames that I myself decided were sharp.  It took 15 minutes to select 80 out of 600 frames but it was well worth it for the final result.
Title: Re: Astro-Cows
Post by: Fay on Sep 08, 2008, 14:18:41
Yes, Mark, as far as I remember, as I don't use Registax that often, I leave up to the program to select the best % that I enter. I have never really looked at 300 frames individually.
Title: Re: Astro-Cows
Post by: Rick on Sep 08, 2008, 14:39:59
Aye. For a relatively bright subject on which you wish to caprure very fine detail you can certainly make a case for taking only the very best few frames. For Jupiter, which rotates relatively quickly, you don't want frames taken over too long an interval either, or the detail will be smeared out.