Re: ATM Are you parallel?

["Bill T." <twentiethwave@hotmail.com>]

James Lerch wrote:
> Question:  How do you determine if your Foucault tester moves parallel to
> the optical axis And the knife edge is perpendicular to the optical axis?

Move the knife edge well inside the focus.  Adjust the knife position so you
see a straight vertical line centered on the mirror.  Move the knife in and
out along the optical axis perhaps 1/2 inch or so.  Adjust the aim of the
whole tester left and right until the line stays centered on the mirror over
the entire range of in-out motion.   Takes just a few seconds.

For the perpendicular, "eyeball" alignment is adequate.

Bill Tondreau