[ATM] 8" f/3.5 !

["Francis J. O'Reilly" <foreilly@bestweb.net>]

Many years ago, probably the mid to late 90's, I ordered a full thickness
8" pyrex pre generated blank from Newport glass. I wanted to build an 8"
f/6 reflector. Unfortunately, I was very tired at the time and asked for a
radius of curvature of 48 inches instead of 96 inches. I ground the blank
out anyway and polished it. The radius of curvature is now 57 inches, focal
length is roughly 28.5 inches. 

I put the glass under the knife tonight, a skill that I never really
mastered, however, I try hard at it, and I determined that the mirror is
most likely spherical, good for a point source, but definately not for
light rays coming from many light years away so as to be nearly parallel
when they strike my mirror. (Isn't space curved anyway Prof. Einstein?)

Any thoughts on the usefulness of this mirror, or am I wasting my time with
something that will never give me much utility?

Best regards to all.

Francis J. O'Reilly 
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