Re: [ATM] Suggestions for a "focus screen" for an optical testbench.

[Jeff Rowe <jroweapp@swbell.net>]

Dear Thomas,
For a quick and cheap test, you might try some frosted tape ( frosted 
side towards the glass, sticky towards the eyepiece),  applied to a 
piece of glass, or across a hole drilled in some sheet metal or Al. A 
regular piece of translucent tape that you have " handled" between your 
fingers might have both transparency as well enough "tooth" to image 
on.   Frosted acetate might work as well.
Just a thought.
Jeffrey


>
>Just trying to find a suitable material to use as the screen that a lens
>under test will focus onto, I'm thinking of using an eye piece to
>examine the image formed to find the "exact focal length" at a given
>frequency. 
>
> 
>
>  
>


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