Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: RobertM on Nov 12, 2008, 19:35:08

Title: A quick visit to California
Post by: RobertM on Nov 12, 2008, 19:35:08
Had to get out and do something last night...

So here is NGC1499 - the California nebula (central portion)

Typically after nearly a month without anything but rain somethings just had to go wrong - leads working loose, guide scope refocusing, battery dying, networking probs and PC not working.  It's funny how the simple things can quickly turn into a trial !  Anyway I finally got setup at 9pm on target and managed 5 x 20 mins before the clouds rolled in.  The moon made things very awkward and the background ADU was very high but thought it was worth publishing as at least it shows something !

Usual culprits:  Sky 90@f/4.5 +SXV-H9 and Astronomik 13nm Ha, Guide setup Skywatcher ED80 + Atik 16IC  captured and guided with MaximDL
DDP Stretched in MaximDL + NR in Photoshop.  The guide scope focuser draw tube is now held in place with a guide ring to stop it moving and I think this helps with tighter stars but the seeing did seem quite good last night despite the moon.

(http://farm4.static.flickr.com/3246/3025710418_5b57558e66_b.jpg)

Full size:

(http://farm4.static.flickr.com/3246/3025710418_3cbc30f0b6_o.jpg)

This isn't an easy object to image despite it's apparent brightness !!!

Title: Re: A quick visit to California
Post by: Mike on Nov 12, 2008, 20:09:57
WoW!!! Fantastic image Robert. Getting better and better.
Title: Re: A quick visit to California
Post by: JohnP on Nov 12, 2008, 20:15:38
Nice one Robert - Looks promising for relatively short exposure with bright moon...(which I expect played havoc with contrast...) Do you plan on getting more of this - maybe a mosaic...?

John
Title: Re: A quick visit to California
Post by: Rocket Pooch on Nov 12, 2008, 20:35:57
Quote from: JohnP on Nov 12, 2008, 20:15:38
Nice one Robert - Looks promising for relatively short exposure with bright moon...(which I expect played havoc with contrast...) Do you plan on getting more of this - maybe a mosaic...?

John

What 20 minute subs short, blimey what are you going to do next?


Title: Re: A quick visit to California
Post by: RobertM on Nov 12, 2008, 22:13:23
Thanks guys, but this really needs 5 hours to get any detail so I wasn't expecting anything too exciting with 100 mins.

John - a mosaic, yes I had thought of that but the full moon needs to get out of the way first.  Also it would take approx 4 shots of 5hrs to get the whole nebula which equates to probably all the clear nights till Christmas.  Tempted - yes, I'll see what the weather does before deciding...

Chris, I was lucky and got no jets across any of the images.  It's certainly tempting to go for the longer subs in order to bet better S/N but it's a risk that's for sure.
Title: Re: A quick visit to California
Post by: MarkS on Nov 12, 2008, 23:33:36

Well done Robert!  To get anything in that bright moonlight last night is quite impressive.  You've captured excelletn detail there.

Mark
Title: Re: A quick visit to California
Post by: MarkS on Nov 13, 2008, 09:02:19

Robert,

One question - why didn't the wind cause you problems?  I set up that night but gave up when the wind played havoc with my guiding.

Mark
Title: Re: A quick visit to California
Post by: JohnP on Nov 13, 2008, 09:40:36
QuoteWhat 20 minute subs short, blimey what are you going to do next?

Chris - I was referring to total exposure not individual subs......
Title: Re: A quick visit to California
Post by: Mike on Nov 13, 2008, 09:44:07
Quote from: MarkS on Nov 13, 2008, 09:02:19

Robert,

One question - why didn't the wind cause you problems?  I set up that night but gave up when the wind played havoc with my guiding.

Mark

Because he has a top of the range mount that is very well engineered and almost bulletproof.
Title: Re: A quick visit to California
Post by: RobertM on Nov 13, 2008, 10:37:49
QuoteBecause he has a top of the range mount that is very well engineered and almost bulletproof.

Yes that does help a lot.  In this case I think a big factor is that a 90mm F5.6 refractor has a miniscule profile compared to an 11" sct with a guide scope on top.  Smaller profile = less wind resistance.
Title: Re: A quick visit to California
Post by: Fay on Nov 13, 2008, 13:34:14
Robert, 20mins exposures!!!! You are the king of long exposures!!!!!!!! Mind you, there is that mount to take into consideration :)

A nice smooth image. Hope you have the patience to do a mosaic, you could be an old man by the time it is finished!
Title: Re: A quick visit to California
Post by: Daniel on Nov 14, 2008, 10:40:53
Lovely image Robert, wonderfull pinpoint stars and smooth fluffy nebulosity in this image, and 20 minute subs!!! was definitely worth it.


would love to see this in a mosaic of the whole thing

Daniel
:O)
Title: Re: A quick visit to California
Post by: RobertM on Nov 19, 2008, 13:27:25
From last night 9 x 20 minute sub exposures , as it should have turned out originally but for the full moon.  It's still a bit noisy and needs another 2 hours or so to really bring some extra detail out.

Medium size:

(http://farm4.static.flickr.com/3022/3042769155_39ab141853_b.jpg)

Large size (warning - it's big!): http://farm4.static.flickr.com/3022/3042769155_882c9789ac_o.jpg (http://farm4.static.flickr.com/3022/3042769155_882c9789ac_o.jpg)

Title: Re: A quick visit to California
Post by: JohnP on Nov 19, 2008, 13:36:18
superb - a lot lot better.... John :-)
Title: Re: A quick visit to California
Post by: Fay on Nov 19, 2008, 14:00:13
Robert, such a lot more detail!
Title: Re: A quick visit to California
Post by: MarkS on Nov 19, 2008, 20:21:52

Very good Robert - a big improvement.  I am SO jealous of those round, coma-free stars!
Title: Re: A quick visit to California
Post by: RobertM on Nov 19, 2008, 21:47:43
Thanks for the positive comments.

Mark, get yourself a quality short focal length refractor - just don't tell the missis how much it cost !
Title: Re: A quick visit to California
Post by: Mac on Nov 19, 2008, 23:51:43
Very nice image,  cant wait to get mine up and running

QuoteLarge size (warning - it's big!):

I'll have to look when i get my broadband back. 160kbps is not fun!!


Title: Re: A quick visit to California
Post by: RobertM on Nov 20, 2008, 13:36:19
Mac, You've had had it for a while, are there any problems ?
Title: Re: A quick visit to California
Post by: Mac on Nov 20, 2008, 20:26:01
sorted, tonight.
I kept telling them it was an exchange fault (I was a subs apps / external BT Engineer), but the call center in india, didn't have that on their
question sheet, so after quite a few calls, and a visit from a BT engineer, who confirmed that it indeed was a fault in the exchange,
its now sorted. AGAIN.

cant realy complain, its the only major broadband fault i've had in 5 years.
Title: Re: A quick visit to California
Post by: Fay on Nov 21, 2008, 09:59:28
Mac, it's funny, but a friend of mine & myself have had broadband problems in the last week & have had to talk to India.