Overlays for star charts

RIGHT ON about telrads and 50 mm minimum size visual....I could not
agree more. IMHO
Clear Skies,
Tom W.



Some people ask me which should I get a telrad
or a finder scope. The Telrad is an absolute must period. There are other
zero power pointing devices, such as the daisy sight. The daisy sight is no
good because it is just a point of light and you can't measure distances
with it. The telrad on the other hand has three circles the smallest is half
a degree, the mid sized is 2 degrees and the largest is 4 degrees. That will
allow for measuring and will make star hoping easier. The finder scope is an
optional luxury that is used in conjunction with the Telrad. If you choose
to get one you will need to have a 50mm objective or larger. The eyepiece
you use to find objects needs to be one degrees or more in field of view. To
find out the field of view of your eyepiece you divide the apparent field of
view by the magnification that eyepiece will yield with your scope. You can
find out the apparent field of view from the manufacture of the eyepiece or
documentation supplied with the eyepiece.