Thread: Wide Field
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Old 22-07-2012, 10:58 AM
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CapturingTheNight (Greg)
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CapturingTheNight is offline
Join Date: Jul 2011
Location: Holbrook, NSW
Posts: 1,230
In the absence of a computer hookup to use software, I use magnified live view to zoom in on the brightest star/planet I can find and manually focus the lens on it until it is as tight as possible, and then switch the lens to AF. I have the camera setup for back button autofocus only meaning that the lens wont try and change focus when I press the shutter button and wont slip focus during the night.

Not sure if the 40d has live view though? (Edit: Well H just said it does)

The other thing you can do is work out the hyperfocal distance of your lens/ camera/aperture combo. There are numerous online calculators for this. The hyperfocal distance given means that if you, say place a flash light or get a friend to hold a flashlight at that distance from the camera and you focus on it- Everything from that distance to infinity (ie. the stars) will be in focus. Add a meter or so to the given distance. Best to sacrifice a meter of focus in the foreground than miss getting infinity.

Hope this helps.
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