ATM Foucault tester

[Andrew Melville <a.melville@mailbox.gu.edu.au>]

Hi

  I have been polishing my mirror with rouge for three hours now. Seems to be going well. However I have had a slitless moveable source Foucault tester for many weeks now and was itching to try it out. I get a strong reflection of the LED but for the life of me I cant make the knife blade intercept the image on the far side of the COC. The mirror is a 200 mm f6 or there abouts so COC should be at about 2400mm. I have tried all the way out to 3000 mm no such luck. I have supplied photos on my webpage

http://www.geocities.com/andrewjmelville/ATM/Foutester/index.html

I copied the design from the Stellafane pages but there are no instructions on how to use it there and the instructions in Texereau are for using a slitted stationary source. If anybody could direct me to a page with good instructions for using a tester such as I have I would be grateful.

 Andrew J. Melville
 
 There are two kinds of tester, 
those who know what they are doing
and me.