ATM Foucault test questions

["Bennett, Thomas D" <thomas.d.bennett@lmco.com>]

Thanks for the advice everyone! - I will try your suggestions.

I'm using the University Optics tester with an adjustable slit, micrometer
knife-edge adjustment longitudinally, and screw knife-edge adjustment
laterally. They did not provide a pin-hole or Ronchi grading nor is there an
intensity adjustment on the light source - I guess these are modifications
that are left up the the ATMers. This tester didn't seem to work at all
until I put tracing paper behind the slit plates to diffuse the light
source. Without the paper in place, the whole mirror seemed to go dark and
light all-at-once without any shadowing effect. Buck mentioned an eyepiece -
the UO tester doesn't have one - would this help in observing the shadowing
and if so, what type of eyepiece should I use?
                        
                                Thanks - Tom