From: "Tom Krajci" 
To: 
Reply-To: "Tom Krajci" 


As scopes get larger, secondary mirrors get larger.

Up to now, mechanical edge clips, supporting the secondary mirror, have
worked well for the amateur.  But as secondary mirrors get larger, and
probably thinner to keep weight down...edge support of a large secondary
mirror will distort the mirror too much and image quality will suffer.

What then?  Upside down 'flotation cell' design for large thin secondary
mirrors...with RTV bonding to the secondary?

What does PLOP say for edge supported mirrors?...at what size/thickness
does image quality begin to degrade?  (I know, secondary mirrors are
elliptical, but PLOP would give us a first approximation.)

Perhaps for big secondary mirror support systems...we may have no choice
but to bond the mirror to the support?  (The secondary hangs upside
down...this seems inescapable to me.)

How do the pro's do it with larger secondary mirrors?

Thanks in advance,
Tom Krajci
Tashkent, Uzbekistan

PS.  Hmmmm, I can see some hard core lovers of slings advocating the use of
slings in secondary mirror supports.  Some ideas die hard.  ;-)


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