Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: Rocket Pooch on Dec 27, 2008, 00:16:43

Title: M42 before the clouds rolled in
Post by: Rocket Pooch on Dec 27, 2008, 00:16:43
Hello,

I did some imaging tonight using the ZS66 and AP .67 reducer giving 260mm focal length at F3.93.  I just wanted to see if it worked.

Guiding was quite irrelevant at this focal length, but I did guide using the ED80 at .3 pixel, and it was windy at times, again irrelevant.  I used the Sphinx SXD, this is a great mount, the build quality is in a different class to the EQ6, now I have the broken bit replaced :-) .

Anyway, 18x5 minute Ha

(http://farm4.static.flickr.com/3239/3139038471_92026c8c71_b.jpg)


Ha + 12x5 minute O3

(http://farm4.static.flickr.com/3118/3139867902_b218f53222_b.jpg)


This is a full size frame, I can't see much curvature it seems to be ok with the 314L, http://farm4.static.flickr.com/3239/3139038471_329c03ebf1_o.jpg
Title: Re: M42 before the clouds rolled in
Post by: Ian on Dec 27, 2008, 00:50:23
looking interesting Chris. Was your OIII a little out of focus or a bit windier maybe? Certainly looks flat enough though :)
Title: Re: M42 before the clouds rolled in
Post by: Daniel on Dec 27, 2008, 02:02:12
That's lovely, a few shorter subs or less aggressive processing for the core and that'll be a beaut!

Daniel
:O)

PS,Im currently on thors helmet, has anyone here managed to get anything on it from our area? I cant see a thing!
Title: Re: M42 before the clouds rolled in
Post by: MarkS on Dec 27, 2008, 07:46:09

It's good to know the ZS66 is seeing some action!    I like the Ha+O3 version.

I think I can detect some coma at the bottom right (tails going off to the right). Or is that something else?
Title: Re: M42 before the clouds rolled in
Post by: Fay on Dec 27, 2008, 08:56:36
Very nice, Chris. I will have to plan Orion imaging as it passes between next door's two tree's!!! :twisted:
Title: Re: M42 before the clouds rolled in
Post by: Rocket Pooch on Dec 27, 2008, 09:47:13
Hi,

Hmm yes I don't think its completely flat and also your right the O3 is a little out of focus, but hey ho, focusing was a laugh because I setup the scope on the decking (never going to do this again) just moving my weight around made the whole scope wobble :-) you would not beleive what I can get away with when the kit is on the pier!  I can jump up and down when the EQ6 is at 2 meters and there no image movement, walking softly on decking at 250mm the stars jump all over the place....

I might buy the ZS66 Field Flattener if I decide to keep the scope for imaging, although I think its a .8 reducer giving 311FL not the 250mm with the AP Reducer, if I'm going to use the scope for very large objects then the 260mm will be better, I can also fix the stars in Photoshop if needed, and add some diffraction spikes along the way as well.

It was cool imaging at F4, didn't have an issue with 1 second exposures in Ha focusing, he he.

Anyway, if its clear tonight I'll setup on the grass and do some more Ha, O3 and SII, and some flats as well.  One thing I did notice is with the O3 there is flare on the ZS66, I don't get this with my ED80 at all?




Title: Re: M42 before the clouds rolled in
Post by: Rocket Pooch on Dec 27, 2008, 09:51:12
Quote from: Daniel on Dec 27, 2008, 02:02:12
That's lovely, a few shorter subs or less aggressive processing for the core and that'll be a beaut!

Daniel
:O)

PS,Im currently on thors helmet, has anyone here managed to get anything on it from our area? I cant see a thing!

Hi,

Not sure about your PS sounds kinky, anyway, I do have 20x25 seconds of Ha and O3 as well, really need to get 20x5 min SII and 20x25sec SII as well.   I have left the camera in the scope just in case its clear again.

I do want to do 16x20 min Ha on the Horse Head to get a good wide field one of those, but that would mean the god of clouds would need to keep away for a whole night.

Chris
Title: Re: M42 before the clouds rolled in
Post by: Fay on Dec 27, 2008, 09:52:47
How can I stop the FR dewing up? The dew strips work a treat on the scopes but the FR can be a problem.

Thanks
Title: Re: M42 before the clouds rolled in
Post by: Rocket Pooch on Dec 27, 2008, 10:20:59
That's odd Fay it does not happen on my scope, you don't keep then in a really warm place do you?

Here's a stack of 22x25 seconds Ha images.

(http://farm4.static.flickr.com/3285/3140999044_5d20944363_b.jpg)
Title: Re: M42 before the clouds rolled in
Post by: Fay on Dec 27, 2008, 11:44:54
No, it is kept in the shed.

I have just dropped my little webcam & broke the fan! John is putting a bit of Araldite on it, at the moment.

I am interested in all your subs for M42, this  one is good.

Chris, I probably have some glue, perhaps Araldite is ok?
Title: Re: M42 before the clouds rolled in
Post by: Rocket Pooch on Dec 30, 2008, 22:54:58
Hi,

I had ago tonight to get the centre in, I need to work on the and also take some flats as well as some S2 as well, so it should come out ok when I know what I'm doing.

(http://farm4.static.flickr.com/3234/3152065296_5065761d5d_b.jpg)

Title: Re: M42 before the clouds rolled in
Post by: MarkS on Dec 31, 2008, 05:40:40

You've merged that core in quite nicely.  It's not an easy thing to do.

Mark
Title: Re: M42 before the clouds rolled in
Post by: Rocket Pooch on Dec 31, 2008, 08:09:10
I really need to take some flats and complete this image but I was holding out for SII as well, not,likely considering the weather.

Title: Re: M42 before the clouds rolled in
Post by: Mike on Dec 31, 2008, 10:18:07
Nice one Chris.
Title: Re: M42 before the clouds rolled in
Post by: RobertM on Dec 31, 2008, 11:22:57
Looking good Chris.  Not sure whether it's my eyes but there does seem to be some coma or flare towards the bottom right.  If it isn't the image then let me know so I can book a trip to the optician...
Title: Re: M42 before the clouds rolled in
Post by: Whitters on Dec 31, 2008, 22:27:41
Nice one Chris
Title: Re: M42 before the clouds rolled in
Post by: Whitters on Dec 31, 2008, 22:30:57
Fay, are you adding your FR to the scope at the beginning of your imaging session or half way through? If you are adding it half way through have you let it cool down or brought it direct from the house?
The Lock 'n Lock containers are great for keeping the dew off while eyepices and filters etc are not in use. See Lakeland Plastics.
Title: Re: M42 before the clouds rolled in
Post by: Fay on Jan 01, 2009, 08:26:45
IT is put on a the beginning of a session, Paul. I notice it when used with the Canon. I will keep an eye on it, & suss out under which conditions I am getting a problem.
Title: Re: M42 before the clouds rolled in
Post by: Rocket Pooch on Jan 01, 2009, 15:02:53
ok when i said the image needs flats, have a look at this

(http://farm4.static.flickr.com/3110/3155555663_91fa679556_o.jpg)
Title: Re: M42 before the clouds rolled in
Post by: RobertM on Jan 01, 2009, 21:21:05
See what you mean!  Any idea what that dark stripe is down the left hand side - I get something similar across one of the longer sides...
Title: Re: M42 before the clouds rolled in
Post by: Fay on Jan 02, 2009, 08:17:36
I have a dark stripe on the left side when using the Atik. 
Title: Re: M42 before the clouds rolled in
Post by: Rocket Pooch on Jan 02, 2009, 09:27:30
Yes its just that the chip ADU's are less there thats all there is about 120ADU difference between the strip and the rest of the image.  Not a problem, you will see on the image with the nebula stars are still there.

Fay don't worry about the strip you can get rid of it as you can see on my processed image.

The key point for me is here in sunny mottingham I have to do flats and flat darks because the signal to noise is allways bad, think about it M42 has to be the brightest object there and its an issue :-(

Nere is a BIAS for the camera, you can see the difference, but remember the ADU difference is 140, this equates to 0.2% flatness of field at full well depth, so you would never see it if the image is very bright.  However if the image is only 2,000 ADU as most of mine from here are then its 7% of the image and is bloody anoying, hence the need for BIAS frames.  Flats are similar in theory.

(http://farm4.static.flickr.com/3080/3159467006_04ed2832b5.jpg)
Title: Re: M42 before the clouds rolled in
Post by: Fay on Jan 02, 2009, 09:32:11
Your M42 is turining out very nice Chris. I like to see how it gets better as you continue the processing.
Title: Re: M42 before the clouds rolled in
Post by: Rocket Pooch on Jan 02, 2009, 09:40:15
ok will put a note up here somewhere, if there was somwhere I could be seen, maybe an image processing page Ian?
Title: Re: M42 before the clouds rolled in
Post by: Ian on Jan 02, 2009, 15:41:50
we bandied around this idea a while back, and I think Rick had a bit of a cogitate about it. There's lots of really useful technical detail locked up in the forum, but there's no easy way to access it other than working with the search. I still quite like the idea of a Wiki, but Rick's not a fan due to the administration overhead. Lets have a chat about it in the pub next time.