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    Re: "Vernier acuity" of horizon IC tests
    From: Douglas Denny
    Date: 2009 Jul 7, 00:31 -0700

    I am aware of the effect of magnification of telescopes.
    I confirm what you wrote about the Snellen chart and moving away to 140 feet is correct.
    
    What interests me, however,  is that the x 7 telescope does not significantly 
    raise the accuracy of celestial sights in the same ratio as the magnification 
    of the telescope as one might expect by your experiment alluded to above.
    
    Without telescope can give around one minute of arc accuracy; with x 7 
    telescope can only improve that to around say 0.4 minute of arc.
    
    Douglas Denny.
    
    
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