[Tweeters] Spotting Scopes and Binoculars - Caveat
diwill at uw.edu
Mon Dec 16 13:54:36 PST 2013
Objective optical testing can determine the "best" scope or binocs in
some theoretical sense for perfect human eyes.
However, few of us have such "perfect" eyes.
Even with glasses or contacts correcting primary refraction errors
(spherical correction) and secondary errors (cylindrical, often called
"astigmatism"), tertiary refraction errors make it imperative to try out
optics yourself before purchase.
A visual comparison of several high quality scopes at a place like
Seattle Audubon is essential.
In particular, try out the scope you are considering buying against
several other high quality scopes.
Sr Research Engineer
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