From: "Rob" 
To: "Richard Schwartz" ,
        
Reply-To: "Rob" 


> I hope you know that the field is flat only when the curve of the primary
> matches the curve of the secondary.

If I understand things correctly (which I probably don't lol) that is one
of the design criteria for an R-C type scope.. They seem to have very low
power secondarys and the radius of curvature is closely matched. Most of
the ones I have seen have around 2.7x secondary compared to something like
5x for a cassagrain.. I just thought matching the curvature was part of the
R-C design...Maybe not though :)

>Everybody makes such a big deal out of R-C optics, the cass builders are
>driven to D-K systems because they are scared away.   But I see nothing in
>the R-C system that is so difficult.  It is certainly no more difficult
than
>the parabolic primary and hyperbolic secondary of a conventional
cassagrain.

This sounds encouraging. The only thing I'm really concerned with at this
point is trying to grind the secondary. Maybe I should try to buy the
secondary???
I've never tryed to grind a cassagrain secondary. Maybe this won't be as
difficult as it seems...

>However, I do suggest that you keep the project to yourself until it is
>done.  If anybody asks, just tell them it is a D-K.   Otherwise, you invite
>ridicule and discouragement.   Also, while you are at it, get all your old
>ATM books that have discouraging words about R-C... and BURN 'em.

I'm a loner for the most part. So theres not really many people around to
tell..Except you guys :)
I think maybe I'll just burn the pages that have discouraging info on R-C
scopes.. The rest of the books seem to have useful info I don't want to
lose hehe :)

Again thanks for the info. you guys have been a huge help :)

Rob

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