Re: [ATM] testing an f/2.6 mirror?

[Jeff Rowe <jeffrowe@austin.rr.com>]

Friends;
I stretched a hair from my head on a piece of window glass and held it 
in place with some tape. I then contact printed this on some high 
contrast film, I then made a contact print of this, which yielded a 
straight thin line on film. I found having the line on film useful 
because the film  was fairly flat, (~.006" thick) and it could be 
positioned, you can also see the return beam come to focus on the film 
base. This helped in positioning the tester. Point is however you make 
your thin line, film is helpful in aligning your tester.
Best
JR

Nils Olof Carlin wrote:

>>>>First you need some fine wire.   
>>>>        
>>>>
>
>Not really - a simple way is taking a piece of acrylic sheet, then run 
>a scalpel-blade along a ruler to inscribe a thin line (turn the line 
>toward the mirror). The thickness of the "wire" can be modulated by the 
>pressure used.
>
>Nils Olof
>
>
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