Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: Fay on Oct 24, 2008, 12:44:02

Title: NGC891
Post by: Fay on Oct 24, 2008, 12:44:02

I was not happy with this image. Would you believe it was 30x300secs!!!!!!I expected more. I used the ED80 & SX M7. No flats as I forgot that when using the SX, images are taken in High Progressive but the flats are done in Interlacing. Hence, my flats were really striped!

Robert, you mentioned it was a bad night 201008, although it looked clear. There are such good versions on UKAI & Johns is such a good one, I thought it would be a lot better than this.

Any idea's why it is has not got more impact?

Thanks,

Fay
 


(http://farm4.static.flickr.com/3166/2968453775_54d76798d0_o.jpg)
Title: Re: NGC891
Post by: Carole on Oct 24, 2008, 13:09:51
QuoteAny idea's why it is has not got more impact?
well firstly because you forgot to post the image Fay.

Carole
Title: Re: NGC891
Post by: RobertM on Oct 24, 2008, 13:41:07
The stars aren't totally round, could that be guiding ...
Title: Re: NGC891
Post by: Mike on Oct 24, 2008, 13:42:01
I can see it. What do you mean by impact Fay? Guiding looks slightly off as the stars are sort of square but apart from that not bad image.
Title: Re: NGC891
Post by: Fay on Oct 24, 2008, 13:45:15
The details are not strong enough, for that many exposures. It was a very damp night, I had to use the hairdryer 21/10.
Title: Re: NGC891
Post by: Mike on Oct 24, 2008, 14:05:00
Then the dew would have upset your guiding as well as producing softer focus. Tryagain on a dry night or use dew heaters.
Title: Re: NGC891
Post by: Fay on Oct 24, 2008, 14:38:40
I will Mike
Title: Re: NGC891
Post by: Mike on Oct 24, 2008, 14:45:47
Do you have a set of dew heaters Fay?
Title: Re: NGC891
Post by: Fay on Oct 24, 2008, 16:03:49
No, Mike, I have a hair dryer
Title: Re: NGC891
Post by: Mike on Oct 24, 2008, 16:22:22
The problem with hair dryers, they are great for getting rid of the dew once it has started to build up, but you really need to prevent it from happening in the first place.

You need a set of dew heaters that can be left on during a session in dewy conditions to stop dew from forming. They can be made relatively cheaply if you don't want to purchase the manufactured items.
Title: Re: NGC891
Post by: Fay on Oct 24, 2008, 16:44:30
You're right Mike. I will check out buying some. The dew does not go for long, using the hair dryer.
Title: Re: NGC891
Post by: Rocket Pooch on Oct 26, 2008, 17:56:33
fay it looks a little out of focus, a bit, also maybe the haor dryer if giving the image a wavey effect
Title: Re: NGC891
Post by: Fay on Oct 26, 2008, 18:25:44
How would the dryer give a wavy effect, Chris? I was not blowing it into style :lol:
Title: Re: NGC891
Post by: Rocket Pooch on Oct 26, 2008, 19:19:25
he he