Re: [ATM] mobsby null test

[Marty.T@t-online.de (Martin Trittelvitz)]

Hallo,
Yes that's the problem, you have to position a grating of 3 mm diameter 
precisely at the correct point in the light path.
The grating that you get from the program from Mark Holm is exactly the 
same tiny grating. Perhaps  you can create a grating with 5 or 7 lines, 
so you get a bigger diameter.
Marty

Guy Brandenburg schrieb:

>So far, I have always used both a series of Ronchi
>tests and also couder-mask knife-edge numerical tests
>and also visual knife-edge foucault tests. I wanted to
>have another test, this Mobsby null test. But I am
>frustrated with the ones from WillBell, which follow
>Mobsby's article very closely. For me, the main
>problem was the fact that the little inverse grating
>was really, really tiny (perhaps 3 mm across total)
>and extremely hard to use. When I get back home, I
>will attempt to use Mark Holm's work instead.
>
>Guy
>

-- 

"Mit der Einführung der Planung ersetzt man den Zufall durch den Irrtum"! (Peter Ustinov)
("By planing you replace hazard by error" Peter Ustinov)

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