Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: RobertM on Jul 28, 2008, 23:04:42

Title: M57, Sheliak and Sulufat
Post by: RobertM on Jul 28, 2008, 23:04:42
The conditions weren't very good but the the neighbours daughter had her 18th birthday so I wasn't exactly going to get any sleep.  This is the first of two that I took last night.


(http://gallery.orpington-astronomy.org.uk/albums/userpics/10031/normal_20080727_M57Widefield_p1.jpg)

This is a link to the 2x2 :
http://gallery.orpington-astronomy.org.uk/displayimage.php?pid=556&fullsize=1 (http://gallery.orpington-astronomy.org.uk/displayimage.php?pid=556&fullsize=1)

Image capture details here:
http://gallery.orpington-astronomy.org.uk/displayimage-556.html (http://gallery.orpington-astronomy.org.uk/displayimage-556.html)

But in summary it's 6 * 5 minutes unguided on the Sky90@f/4.5.

Thanks for looking.
Title: Re: M57, Sheliak and Sulufat
Post by: JohnP on Jul 28, 2008, 23:10:40
Nice Robert - I like the widefield - John
Title: Re: M57, Sheliak and Sulufat
Post by: Mike on Jul 29, 2008, 05:57:51
Nice one Robert.
Title: Re: M57, Sheliak and Sulufat
Post by: RobertM on Jul 29, 2008, 07:24:09
Thanks guys.  I made a mistake on this by not resetting the ISO so the subs were done at ISO 200 rather than the intended 800, it definitely makes a difference and that's why all the faint stars are so weak.  It's not a spectacular starfield but I wanted to see what the field of view was and get an idea of exposure lengths before DSC.  It's also about time I posted something.

One thing is certain though, I do need to modify this camera !
Title: Re: M57, Sheliak and Sulufat
Post by: Ian on Jul 29, 2008, 09:30:47
Quote from: RobertM on Jul 29, 2008, 07:24:09

One thing is certain though, I do need to modify this camera !


Sounds like a job for DSC!

The image you've posted on here is good, but the full scaled one is even better. You're right about not pulling out the faint stars, you get a hint of them in the full scale one. The focus looks good and the colour in the ring is very subtle. I'd be happy with that :D

Title: Re: M57, Sheliak and Sulufat
Post by: Fay on Jul 29, 2008, 09:42:37
Really nice, Robert, change to see a nice airy widefield shot.
It came out nice.

Fay
Title: Re: M57, Sheliak and Sulufat
Post by: RobertM on Jul 29, 2008, 13:56:48
QuoteThe image you've posted on here is good, but the full scaled one is even better.

Ian, the full scaled one in the gallery is actually the half size one (binned 2x2).  The full sized image shows detail in the ring and the faint central star but I need at least double the number of subs to bring out the background starfield.  Will try to do this if the weather plays ball.
Title: Re: M57, Sheliak and Sulufat
Post by: Mike on Jul 29, 2008, 14:09:23
Get the full sized one on the gallery too. That's what it's there for !
Title: Re: M57, Sheliak and Sulufat
Post by: Ian on Jul 29, 2008, 14:22:59
wot Mike sez :D
Title: Re: M57, Sheliak and Sulufat
Post by: RobertM on Jul 29, 2008, 14:43:03
But it don't like it, at 12Mpix me pic is just too big !
Title: Re: M57, Sheliak and Sulufat
Post by: Rick on Jul 29, 2008, 17:37:20
See this new FAQ thread (http://forum.orpington-astronomy.org.uk/index.php?topic=3657.0) ;)

How big (format, pixels and actual file size) is your full-sized image?
Title: Re: M57, Sheliak and Sulufat
Post by: MarkS on Jul 29, 2008, 17:39:14
Robert,

It's unusual to see M57 at such a scale - it gives an interesting perspective.  Nice image.

Mark
Title: Re: M57, Sheliak and Sulufat
Post by: RobertM on Jul 29, 2008, 18:05:44
Full size image is 4290 * 2856 pixels, I won't know about the full file size till I get home but the jpg is probably a couple of Mb (with medium high compression).
Title: Re: M57, Sheliak and Sulufat
Post by: Rick on Jul 29, 2008, 19:51:49
Ok. It'd be the 4290 that it's complaining about. I'll tweak something...

...and I've now tweaked the maximum dimension. Please give it another go.