Re: ATM Vacuum Pans. _ Corrector size?

[Aplanatic@aol.com]

Ken Lowther wrote:

> Hmmmm.  Just when I thought I had it all figured out. :(  Actually this
>  might not be as bad as I first thought.  I suppose I could grind the
>  sphere before machining out the pan.  However, pracitcal experience from
>  others may indicate that this is over kill. :)

Sorry, Ken, this doesn't work very well.  Grinding is performed on the 
deflected plate so that it doesn't take an age to polish-in the desired 
second- plus fourth-order figure.  If you attempt to grind-in the appropriate 
sphere before deflection, you will be left with a whole potfull of glass to 
get rid of by polishing.

Dave Rowe
Torrance, CA