Re: ATM Caustic Zone Length

[Ken Lowther <s0109366@cc.ysu.edu>]

On Thu, 3 Jul 1997, John H. Svensson wrote:

> Pardon the newbie question which follows but to clear uo/p a seeming
> discrepancy for others who may just be getting started on their first mirror:
> Someone on the list referred to Berry's recommended "72 strokes" to 
> parabolize from a sphere, Tex states it's about an hour's job on an 8",
> certainly more than 72 strokes even at a moderate 25 per minute rate.  Who's
> right here, or at least who is closer to the mark for the average polisher?
> I ask because I'm using Tex and set off on about 2 , 10minute "classis/c
> stroke" sessions expecting it to be about 45 minutes to be close for a 6",
> my central ray to marginal ray focus images don't seem to be coming down
> toward my theoretical .09 inch caustic zone.  Have I inadvertently gone
> hyperbolic? TIA.  
> jhs
> 

Berry's recomendation I think is for Cerium while the Texereau was using
rouge.

Ken Lowther  
s0109366@cc.ysu.edu
Youngstown, Ohio  USA