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Help with Long Exposure.

Started by SunSpot51, 08/19/2005 01:43AM
Posted 08/19/2005 01:43AM Opening Post
Hi all,

I am primarily a planetary imager, but I have some desire to do some long exposure imaging. Primarily I want to try for planetary satelites (Deimos, Phobos, etc). I have a Mewlon 250 and one of my cameras is an Atik 1HS. The other night I shot Mars at prime focus with 15 ten second frames and only got a brigher Mars. Forgetting for the moment about flats and darks, what sort of suggestions can I get on how to be more successful. Am I better off doing fewer frames, but longer (say 10 one minute exposures) or many more shorter exposures (say 100 ten second exposures). What about settings, gain, brightness, etc. As soon as I can get that going I'll get into the other issues with flats and darks, etc.

Any suggestions are most helpful!!

Thanks again!
Paul Maxson

Paul Maxson
Moderator - CCD Imaging and Processing/Solar System
Celestron C14, Mewlon 250, Orion EON120, ASI120MM, Flea3.
http://www.sunspot51.com
Posted 08/19/2005 02:25AM #1
Considering read noise and bias left over I would suggest you go with the longer 1 minute exposures. They have the least amount of "issues" in my opinion and their will be less that you need to work with.
Eric
Posted 08/19/2005 02:26AM #2
Paul, first you need is a occulting spot or bar in the prime focal plane to blot out the planetary disc. This is true for the gas giants as well. This is usually mounted inside a special or modified eyepiece and uses eyepiece projection. A bar is easier to construct and is usually a tiny strip if blackened metal mounted in front of the lens elements of an eyepiece that has the focal plane there. You may google around for anybody doing the planetary moon spotting. Joe.
Posted 08/19/2005 02:33AM #3
Paul, try the folks in the CCD Imaging and Processing/ Solar System forum. Joe