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Focus Hints for digital camera astro work

Started by Alex McConahay, 03/22/2004 01:10AM
Posted 03/22/2004 01:10AM Opening Post
Anybody know of the best ways to get a digital camera to focus well with a telescope for astrophotography? I am interested in all suggestions, and will try what I get. Links to websites welcome, or just tell me how you do it in a posting.

(I am using Nikon Coolpix 5400, Maxview II, and various scopes. Have hooked output to television. Still do not have good focus, and certainly not easy focus--and I don't want to have to carry around a television to focus astrophotos.)

Thanks in advance,

Alex
Posted 03/22/2004 05:35AM #1
Alex,
I too have been searching for the 'best' method of focusing my digital camera. I use a Nikon 4500 and to date have had the most success using this method:
Step 1, focus the eyepiece to be used by eye, just as in viewing.
Step 2, set the cameras focus at infinity (the mountain symbol)
Step 3, attach camera and use the zoom, don't be affraid at this point to use the cameras digital zoom. Jose Suro has been posting some great images and he has been stacking multiple images taken at full digital zoom.
Step 4, if necessary (always in my case with my aged eyes) do a final tweaking of focus using the telescopes focuser.
Then you can back off on the zoom if needed for proper composition.
My camera has a terrible time trying to focus if I use the auto focus. I don't know if I got a bad camera or if it is a common problem in this model under low light conditions.
I have read where others use the auto focus with good results so I look foward to reading some more responses to your post.
Hope this gives you at least a starting point and good luck with your imaging.
Bob

Fujinon 10x70 FMT-SX binocs
Tak FS-78 ƒ/8.1 - 630mm fl.
6" ƒ/6.5 homeground newt. - 981mm fl.
10" ƒ/4.85 homeground dob. - 1231mm fl.