Re: ATM Am I done yet?

["Dave McCarter" <dmccarter@sympatico.ca>]

> GO SLOW when you are "almost there".  My mistake was to be too
> aggressive in the final stages of figuring...

While there may be "pros" who feel comfortable about slapping the figure
onto the mirror in a few sessions, I think the key to a good figure is both
going slowly and deliberately. I find that a slow smooth lap movement
results in a smooth surface. Take lots of time for testing. Let the mirror
settle down for several hours before looking at the figure. You can't figure
better than you can measure. Look at the surface directly, with a Ronchi
grid, and with a pin stick or a mask. And above all, think about what the
surface is doing, how your lap is working, what movements will do what you
need. If something is not clear to you, ask others, read your books, or
leave it for a time.

Good optical surfaces don't happen overnight. They take lots of time, which
is why really good mirrors are worth a lot.

Dave