Re: ATM Lateral Wire Test

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

The Lateral Wire Test needs a slit of about 75% or more of the width of the
wire.  You are basically doing a double Foucault test with this setup in
some ways so that you do indeed to have both sides of the slit to do the
test.  The reduction of size of the slit over the wire determines the width
and depth of the ring produced on the mirror surface.
Or are you talking about the Caustic Test?
In any case, if you're having dim image problem, that is easily cured by
more light in the system.  You may also want to put a video camera behind
the wire and adjust the light level to where it almost makes the camera's
automatic control of brightness start working.
Bob May
http://nav.to/bobmay
bobmay@nethere.com
NEW! http://bobmay.astronomy.net