Re: [APML] 8" Schmidt camera on Astromart

[Aplanatic@aol.com]

Kent,

> Ideal????
>  I'm not sure.
>  As everyone usually knows, the Celestron/Epoch Schmidt's were/are f 1.5's.
>  This is great for very short exposure times, but makes focusing 
problematic 
>  because there is no room for any error. In fact, although they have invar 
>  rods, I have to adjust my Schmidt's focus twice a year, for cold weather 
and 
>  hot weather.

I'm not sure either, that's why I asked.  It seems to me that something 
around f/2.5 would be perfect, making the OTA about 40" long.  A higher focal 
ratio would make focusing that much easier.  Or is speed and field-of-view 
more important?  Opinions?

It's interesting to learn about the summer/winter focusing changes, thanks.

Dave Rowe

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