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Re: Side Error
From: Frank Reed CT
Date: 2005 Mar 22, 18:06 EST
From: Frank Reed CT
Date: 2005 Mar 22, 18:06 EST
Bill you wrote:
"My question, can I use any sharp line to test/adjust even if it is
only
several hundred yards away? My guess is yes, as parallax between the
horizon and index mirrors should not be a problem, but my guesses are so
often in error."
several hundred yards away? My guess is yes, as parallax between the
horizon and index mirrors should not be a problem, but my guesses are so
often in error."
Since your post is titled "side error", I assume that you're lining up the
direct and reflected image of a vertical line, and yes, in that case parallax in
the instrument is no problem. BUT in my opinion, side error is no problem and a
little mismatch (maybe one minute of arc) in the direct and reflected images may
actually be useful in some circumstances.
-FER
42.0N 87.7W, or 41.4N 72.1W.
www.HistoricalAtlas.com/lunars
42.0N 87.7W, or 41.4N 72.1W.
www.HistoricalAtlas.com/lunars
