Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: Ivor on Mar 30, 2012, 23:15:00

Title: IC443 - Jellyfish nebula
Post by: Ivor on Mar 30, 2012, 23:15:00
Fancied giving this a go before it disappeared but I only managed a few subs but I'm pleased with what I managed with the limited data. I took a couple of S-II subs (there no O-III I discovered as well) hoping to go back for more but the nights were against me, I'll be going back later in the year to try again.

(http://gallery.orpington-astronomy.org.uk/albums/userpics/10056/normal_ic443_H-A.jpg)

4 x 10mins HA ST8300M FLT110



Title: Re: IC443 - Jellyfish nebula
Post by: MarkS on Mar 31, 2012, 10:40:53

Ivor,

That's looking really good even with such a small integration time.

Nice one!

Mark
Title: Re: IC443 - Jellyfish nebula
Post by: RobertM on Mar 31, 2012, 13:47:19
Yes, I'd agree with Mark, that's an excellent start.  There's a bit of coma showing in the corners but not too bad.

Robert
Title: Re: IC443 - Jellyfish nebula
Post by: Ivor on Mar 31, 2012, 15:08:43
Thanks for the feedback. I started getting the coma since swapping from the DSLR and I thought it meant I needed to adjust the Reducer/Flattener I've playing around with it but all that happens was the stars went out of focus. Is it caused by the chip size change and is there anything I can do to get around it preprocessing?

Title: Re: IC443 - Jellyfish nebula
Post by: Fay on Mar 31, 2012, 16:31:04
That is really good Ivor!
Title: Re: IC443 - Jellyfish nebula
Post by: MarkS on Mar 31, 2012, 22:24:48
Quote from: Ivor
Thanks for the feedback. I started getting the coma since swapping from the DSLR and I thought it meant I needed to adjust the Reducer/Flattener I've playing around with it but all that happens was the stars went out of focus. Is it caused by the chip size change and is there anything I can do to get around it preprocessing?

Which scope and reducer are you using.  If the DSLR produced coma free images, is it possible that the reducer to CCD distance is different for the new camera?

Mark
Title: Re: IC443 - Jellyfish nebula
Post by: Ivor on Apr 01, 2012, 08:18:46
I'm using the FLT110 and the WO reducer/Flatener IV
http://www.williamoptics.com/accessories/flattener4_features.php (http://www.williamoptics.com/accessories/flattener4_features.php)

How do you work out the distance required?
Title: Re: IC443 - Jellyfish nebula
Post by: Rocket Pooch on Apr 01, 2012, 12:08:02
Ivor,

You dial in the distance on that one say 60mm and then space from the bottom of it to the film place, at 60mm it has to be 60mm +- 1mm to get round stars.

Chris