Re: ATM 12" F2 mystery mirror

["Peter D. Brooks" <pdbrooks@pacbell.net>]

> William Kelley wrote:
> 
> I have acquired (as a gift) a 12- 3/16",  F2 , mirror apparently of Pyrex and
> 1 -1/3" thick. 

[snip]
F> course, determine the figure- but with this much- does anyone have any idea
> what it might have been used for?

Not sure, but I've seen some *very* fast mirrors used in Integrated circuit
fabs in the projection aligners.  I have what started as a 10" F0.6 mirror that
came from a 4" projection aligner.  (Had to cut it down to 9" since the 10"
section would disappear when degenerated to a longer mirror.  The invar(!) ring
surrounded a 9" spot, but the outer 1/2" overlapped.  BTW, this is zerodur.)

Consider a schmidt camera.  IIRC, ATMT has some plausible designs.

Pete Brooks