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Captured by
Douglas Rollain

Lion Nebula SH2-132 - RC71

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Posts Made By: Jim Thommes

June 11, 2007 03:44 AM Forum: CCD Imaging and Processing/Deep Sky

NGC 6720 in Narrowband

Posted By Jim Thommes
Dan,
Excellent image. I love the deep shots with narrow bands for this object. I actually prefer the CFHT, but it doesn't seem to be as popular.


June 12, 2007 06:40 AM Forum: CCD Imaging and Processing/Deep Sky

NGC 4725

Posted By Jim Thommes
Thanks for the comments folks...

Louie,
Yeah, this image is typical of my short data sets. I think I 'm going to have to demonstrate some patience and get some longer data on some of the objects.

Eric,
I thought I was the only one to sit on data like I do. don't keep us waiting until next winter though.

June 17, 2007 10:00 PM Forum: CCD Imaging and Processing/Deep Sky

NGC 6188

Posted By Jim Thommes
Very nice Louie. Congrats to both you and Bud.

June 17, 2007 10:03 PM Forum: CCD Imaging and Processing/Deep Sky

Eagle Nebula

Posted By Jim Thommes
Greg,
Very nice Eagle!

Are you shooting through holes inn the clouds or a consistently clear sky after 3:00 AM?

June 17, 2007 10:05 PM Forum: CCD Imaging and Processing/Deep Sky

Viel Nebula in Narrowband

Posted By Jim Thommes
Wayne,
Very nice! How are the colors mapped?


June 17, 2007 10:08 PM Forum: CCD Imaging and Processing/Deep Sky

NGC7023 and regional dust

Posted By Jim Thommes
Tom,
Looking really good. I like the wider field in the link over that of the attachment. Looks like you had great data and processed well.

June 19, 2007 04:10 AM Forum: CCD Imaging and Processing/Deep Sky

First autoguided images - M13 and M51

Posted By Jim Thommes
Eric,
Nice images and congrats on the Autoguiding. It is a simple principle in concept but can be a challenge to achieve in a practical sense.

I will throw in my thought here on things to check. I see you use a separate guidescope. I am curious as to how the two OTAs are mounted. My bigest challenge with autoguiding accuracy has been differential flexure of the two OTAs. That's what can also cause different guiding behaviors at differnt parts of the sky. The symptom is a long term drift (on the imager) while the guider is dead nuts. The drift acan be in any direction though - not just RA.

If the RA motion of a couple of pixels is evident in the guiding trace, and is back and fourth, it is not flexure. I note you have a G11. They can be kind of jumpy and want a higher correction rate. What is your correction rate?

Also, I think you have the "East side heavy" OK if you are taking a 21 lb counterweight 1/2 inch off balance on a G11.


June 19, 2007 04:15 AM Forum: CCD Imaging and Processing/Deep Sky

NGC 5247 Galaxy

Posted By Jim Thommes
Thanks folks for th comments...

Larry, Thanks for taking a look at some of the other images on my website. The gallery spans several evolutions of equipment and can range quit a bit in quality. I kind of like to keep the old stuff out there - its fun to look at from the old stuff from time to time.

July 1, 2007 06:44 PM Forum: CCD Imaging and Processing/Deep Sky

Coma Cluster

Posted By Jim Thommes
A belated thanks for the comments on the image....

I have been out of town for this last week doing some fun things in the Sna Juan Islands - no internet access. Now I need to catch up with the forum a bit.

July 2, 2007 04:09 AM Forum: CCD Imaging and Processing/Deep Sky

M8 and M20

Posted By Jim Thommes
Eric,
It looks pretty good as just the RGB as you say. Congrats.

I gather from your comment that the image presented is the balanced image. Did you have a full image unbalance toward green or did you have to balance portions of the image separately? I have found that varible high clouds can really give me trouble with an uneven balance over the full image.

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