To: "Dwight K. Elvey" ,atm{at}shore.net
From: Mark Suchting 
Reply-To: Mark Suchting 


At 11:38 AM 23/12/2002 -0800, Dwight K. Elvey wrote:
>  On a
>cold winter night, one can clearly see the difference,
>looking at Saturn with 120X. There is a distinct
>difference in contrast. During summer usage, the
>distinction isn't quite as clear.

In  Sydney , Australia night time variation  between Summer and Winter only
differs by 6 or 7 degrees C.  Being able to observe without heavy clothing
( causing a `boiling kettle' effect ) probably helps a lot with the plume
effect.

>My guess is that you'll find that the
>thermal plumes will be the least of your problems
>in making a bino scope.

And perhaps the least of your distractions in actually using it.

~Mark Suchting

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