To: Chuck Dethloff ,atm{at}shore.net
From: Mark Suchting 
Reply-To: Mark Suchting 


At 09:13 AM 23/12/2002 -0800, Chuck Dethloff wrote:

>I have never owned a binoscope, but can attest that on a few occasions I
>definitely have seen an effect in the quality of higher power planetary
>images when folks were standing in front of my Dobsonians at star parties.
>After asking them to please move the image improved in these instances. No
>imagination needed to see the difference either.
>
>So, while this may not be a problem most of the time for low to moderate
>power viewing (I accept the real world evidence offered from Clive, Marty
>and others), I don't think that one can say it could never be a problem.

Chuck

I don't believe anyone is saying potential heat plumes do not exist or have
an effect.  And I'd add that my 8" binocular had 14" long hoods
past the focuser.   At the same time I think with a true binocular
instrument that
the best detail seen in either eye at any instant is used to build up a
more stable image. My planetary views were always more detailed with two
eyes than one, so my real world  experience is that there may be some loss
in some circumstances as well as some gain again viewing with two different
light paths.

This thread has bogged down in a criticism of a particular style of
binocular with a  focus on optimal planetary observing. Don't you guys ever
have heat of rooftops, concrete slabs, driveways etc to contend with ?  We
don't live in a perfect world. Perhaps with the level of light pollution in
the Northern Hemisphere , you have to concentrate much more on looking at
the Planets,  but I know it wouldn't account for more than 2% of my
observing time.  It probably needs to be reiterated that a large binocular
telescope excels best for Deep Sky observing and probably not worth the
effort if you are focused mainly on  planetary observing.

~Mark Suchting

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