Re: ATM First light!!!

[Bruce Swayze <swayze@europa.com>]

At 07:46 AM 7/17/97 -0400, you wrote:
>
>I have a 6" f8 mirror that I want to regrind down to an F5 or possibly an
>f4. How difficult would figuring these be compared to the 10"? Would common
>sense point me toward one or the other?

Darwin,

We have been asked this question before, and the common sense thing to
consider is that you have a mirror that is presumably pretty good.  It has a
lot more value than a raw glass blank, since it has many hours of work and
labor put into it (just compare prices between a finished mirror and a glass
blank).  

By regrinding a perfectly good mirror, you immediately reduce it's value to
that of a raw glass blank, and you must put the labor into it to bring the
value back up.  The sensible thing to do is to just buy a blank (a 6" blank
is very cheap) and grind the f/5 mirror you want.  Sell the other mirror
that you now have and pocket the difference.  

Even if the existing mirror isn't that good, the sensible thing to do is to
refigure it until it _is_ good, and still grind the f/5 mirror that you want.

Hope this helps.

Bruce Swayze
swayze@europa.com
http://www.europa.com/~swayze    Swayze Optical home page