Re: [APML] Trailed Stars, Large Errors: Help for a Newbie

[Roland Roberts <roland@astrofoto.org>]

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>>>>> "Yi-Zen" == Yi-Zen Chu; Yiren Qu <yi-zen.chu@yale.edu> writes:

    Yi-Zen> Second problem: almost all my shots (except one) came back
    Yi-Zen> with trailed stars. The longer exposures seem to have the
    Yi-Zen> longer trails. (I shot mostly with 55mm and 180mm lenses,
    Yi-Zen> and also through the Borg at 640mm.)

If you are seeing trailing with a 55mm lens I would suspect the polar
alignment.  I've shot on 35mm film with a 50mm lens and even before I
had a clue about how important polar alignment was good decent
results.  It was dumb luck as much as anything, but the real point is
that trailing on film with a 55mm lens is almost certainly an
alignment problem.

Other things *could* be a problem (was the scope balanced, was
everything tightened down), but alignment would be the first place to
start.

roland
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Roland B. Roberts, PhD                             RL Enterprises
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