Re: ATM Robo-Foucault, Image intensity, and Changing knife edge readings

["Bob May" <bobmay@nethere.com>]

Several things that need to be mentioned:
The slit limits the amount of brightness that the return will eventually
attain.  A slitless will have an asymetrical upper limit for brightness as
more of the light source becomes unmasked by the KE moving aside from the
return.
When looking at the actual cutoff, it doesn't matter whether there is a slit
or not as the second edge of the slit isn't used in the actual shadowing of
the return.
As such, it may be that the need for a real slit may be needed to attain an
even brightness range from bright to dim in the RoboFoucault tester.
Bob May
http://nav.to/bobmay
bobmay@nethere.com
NEW! http://bobmay.astronomy.net