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Astrophotography and Sketching >> DSLR & Digital Camera Astro Imaging & Processing

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CharlesW
Pooh-Bah


Reged: 11/02/12

Loc: Chula Vista & Indio, CA
Blue ring artifact
      #5613968 - 01/09/13 03:58 PM Attachment (16 downloads)

I'm really new to all this but I think things are coming together a little. I have some questions I'd like to ask if I may? My imaging train so far is a CPC 800, 2X (2") barlow, and a Canon 50D. I'm controlling the 50D through BackyardEOS. I've had problems eyeballing a bright enough image through liveview, so I take a quick 500 frames, run them through Castrator, and then open that in VirtualDub to get a histogram. Last night I finally settled on iso 800 with 1/40 shutter speed. Then I take 2000 frames, run that through VirtualDub to massage the histogram a little, and then open in Registax. I then use on of the RankinStudio Youtube guides to process in Registax. As soon as I start applying wavelets I get a blue ring around the inner circumference of the planet. I can't seem to get rid of that ring, and that's before PS Elements. My questions are:
1) Should I keep up with the 2" image train or go to a 1.25" run?
2) If anyone is using a similar scope, camera, and BYE, would you share what iso and shuttler setting you find successful?
3) Is all the stuff with Castrator and VirtualDub unnecessary?


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Rankinstudio
Carpal Tunnel
*****

Reged: 04/05/08

Loc: Southern UT
Re: Blue ring artifact new [Re: CharlesW]
      #5614200 - 01/09/13 06:15 PM

Hi,

The ring artifact is common when pushing data from below average seeing conditions really hard. If you have to really crank up the wavelets to get any detail out, the softening / sharping routines cause that ring artifact. If you hang out on the planetary forum you will see it a lot from images posted in bad seeing. It may also be worse if the image is under exposed.

With planetary, proper collimation and seeing conditions rule.

Nothing wrong with keeping the 2" imaging train.
You don't have to use castrator, as I state in the video I only use it to cut down on file size. I can end up with 30 gigs of videos from one imaging session.

Keep an eye on clear sky clock's forecasts. I won't even setup for planetary work unless the seeing is forecast to be 4/5 5/5. Getting a night of good seeing is not as common as you may think, but you will know when you get one!

Cheers!


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CharlesW
Pooh-Bah


Reged: 11/02/12

Loc: Chula Vista & Indio, CA
Re: Blue ring artifact new [Re: Rankinstudio]
      #5614302 - 01/09/13 07:04 PM

Thank you, Sir. The videos are extremely helpful for a newb.

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Rankinstudio
Carpal Tunnel
*****

Reged: 04/05/08

Loc: Southern UT
Re: Blue ring artifact new [Re: CharlesW]
      #5614307 - 01/09/13 07:07 PM

Here is an example from a very regular poster over on the planetary imaging forum:

http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/5614289/page...

You can make out some bad ring artifacts in his images. It's all about the seeing!

Glad you found the videos useful

Cheers!


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