Re: [ATM] Quartz test

[Guy Brandenburg <gfbrandenburg@yahoo.com>]

Could one use something like a small (4" diam) cassegrain telescope to put out a collimated, parallel beam from a laser pointer for testing purposes?

Mike Lockwood <melockwo@uiuc.edu> wrote: Gary,

The collimator puts out a 24" diameter beam of collimated light, that 
is, light that is parallel, like star light.  The 4.25" sits in front 
of it, collecting a small portion of the beam to form a "star" image. 
  I put a ronchi grating in the focuser to get the ronchi image later 
in the page.

The quartz was right in front of the 4.25" as an optical window would be.

You can view the star image directly with a welding filter and an 
eyepiece.  It is not bright enough to damage vision, but it's not 
pleasant to view directly.

 Mike Lockwood




Guy Brandenburg, Washington, DC
My home page on astronomy, mathematics, education:
http://home.earthlink.net/~gfbranden/GFB_Home_Page.html
or else 
http://tinyurl.com/r6fh2

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