[ATM] Quartz test
Guy Brandenburg
gfbrandenburg at yahoo.com
Tue Aug 7 05:37:09 JST 2007
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 at 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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