"Ralph Hertle" wrote in message
...
Chuck Taylor:

Are reticles possible for say 10" Newtonian reflecting telescopes that
would enable angular measurements to be made?

Reticle eyepieces are available commercially. They can also be made by
placing the reticle at the focal plane

See http://www.skywatch.co.za/instruments/micrometer/ for building a filar
micrometer

Clear Skies

Chuck Taylor
Do you observe the moon?
Try the Lunar Observing Group
http://groups.yahoo.com/group/lunar-observing/
Lunar Picture of the Day http://www.lpod.org/
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Could reticles be made? How could they be adapted or made visible in a
telescope's optical system?

Reticles are used in optical comparators for use in measuring small
widths on small industrial parts. Reticles are precise arrangements of
thin lines or measurement scales that are viewable through telescopes
and microscopes. The classic movie image is the view through the
periscope of a submarine, and the reticle is used to decide direction of
view and sizes of objects, for example.

Ralph Hertle