Re: [ATM] Suggestions for a "focus screen" for an optical testbench.

[Jim Burrows <burrjaw@earthlink.net>]

At 2005-10-24 08:34 +1000, Thomas Janstrom wrote:

>The thing with CeO2 is that it's much softer than glass so it doesn't
>actually grind the glass like a harder "abrasive" will. For that matter
>no-one is *really* sure how polishing takes place anyway, there are many
>theories, but as you can't see it happening at the near molecular level
>you can't really prove one or another.

Somewhere in the ancient A.T.M. books (using their abbreviation - avoids 
modern conflict with ATM machines), it says that rouge will grind glass if 
the substrate is glass or metal instead of pitch, and, on pitch, the 
smaller AlO2 or carbide grits will do a poor polishing job.  This backs up, 
to me, the planing theory of polishing (Tex, p. 21).  Would somebody with a 
couple chunks of glass (window or microscope slides) and some CeO2 check 
whether it really is softer than glass or produces a couple of pieces of 
ground glass?

         -- Jim Burrows
         -- mailto://burrjaw@earthlink.net
         -- http://home.earthlink.net/~burrjaw
         -- Seattle N47.4723 W122.3662 (WGS84)  

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