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Re: ATM 85 1/4?


Since it says "R," it's probably a radius of curvature in inches.  So the
focal distance would be half of that, or 42 5/8 inches.  Does that work out
better?

--Spencer Roedder

At 02:19 PM 6/16/99 -0700, Slc.Dennis Bishop wrote:
>
> on the back of mirror of that dob that I got yesterday, there is
>
> R = 85  1/4
>
> I figured that was in meters, so that converts to 33.56 inch. Now
>taking my tape I messure off 33 1/2 to get a ballpark look at the
>setup, BUT! at that setting,(if I'm right) the mirror to eyepice
>holder is more like 34 or 35 inch and where the small mirror would be
>is another 1/4 inch. am I right in thinking the small mirror is
>catching the cone of light after a focul point? is this right? or does
>the eyepice holder need to be moved downward? or am  I totaly off
>base?
>
>
>
>*---------------------------------------------*
>| Slc.Dennis Bishop Founder & Lifetime Member |
>| SIAR (1971)   /  IAR (1995                  |
>*---------------------------------------------*
>
>
>