Thread: Messier 7
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Old 01-05-2016, 09:01 PM
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Luke.
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Join Date: Apr 2016
Location: Melbourne
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Quote:
Originally Posted by raymo View Post
Sorry, what I was saying about focuser sag is not relevant, I had forgotten
that you weren't shooting through a scope, but through a lens.
That puts a whole new slant on it. I can't imagine your camera's optical
train is faulty. That leaves a camera that is not mounted solidly enough,
or a million to one shot of a faulty lens[virtually no chance],
raymo
Quote:
Originally Posted by Mickoid View Post
Luke I assume you just had your camera on a tripod. With that focal length lens 1 sec is probably the maximum you can go without your stars looking like eggs. There is somewhere on the net I remember reading which gave maximum times for each particular focal length lens before stars were no longer round. Obviously the shorter/wide angled lenses gave greater exposure times than the longer focal length ones. You've probably done the best you could have achieved with your lens at 300mm fl on a tripod.
Yeah on a tripod. It is not flimsy but it could certainly be more sturdy which would probably help a fair bit.
If I went to 1.3" the stars looked a lot worse. The rule I was using was focal length / 500 which I had to reduce anyway.
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