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Old 29-04-2009, 10:31 AM
Dennis
Dazzled by the Cosmos.

Dennis is offline
 
Join Date: May 2005
Location: Brisbane
Posts: 10,918
Quote:
Originally Posted by sjen2004 View Post
I've been trying to take images of Saturn with the neximage on the dob but all I get is a bright fuzzy blob. I don't want to spend more money until I can use this CCD better.

Regards Simon
If you’re getting a bright blob with the NexImage, then I suspect you’ll also produce a bright fuzzy blob with any of the D*K series of cameras!

I started off with a Philips ToUcam 840K which I think has a similar CCD chip to the NexImage, and when I first started taking images of Saturn, Mars & Jupiter I also suffered the bright fuzzy blob syndrome. Generally, I’ve found the following factors contribute to the bright fuzzy blob result:
  • Poor focus.
  • Poor seeing combined with low altitude.
  • Poor collimation.
  • Incorrect exposure, Gain, Gamma or all 3!
Let me say from the start that you’re doing it tough with a non-driven dobsonian, as you have to focus and nudge the ‘scope at the same time, which requires considerable skills.

As Mike has wisely suggested, start on the Moon and become familiar with getting good focus and dialing in the camera settings to obtain the correct exposure. You’ll then find that the skills you’ve gained can be put to good use on the smaller and more difficult planets. Good luck!

Cheers

Dennis
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