Re: ATM Exit Pupils & Big Scopes

[Richard Schwartz <richas@chelsea.ios.com>]

-- [ From: Richard Schwartz * EMC.Ver #2.5.02 ] --


-------- REPLY, Original message follows --------

Date: Wednesday, 14-Aug-96 02:55 PM

From: M.E. Germann             \ Internet:    (ccmeg@mizzou1.missouri.edu)
To:   atm@shore.net            \ Internet:    (atm@shore.net)

Subject: ATM Exit Pupils & Big Scopes

Exit Pupils & Big Scopes --

Val Germann
Central Missouri Astronomical Association

Back in the early 1980s, when the Coulter big dobs first
came out, we began to see problems due to the power being
too low and exit pupil too large.  I ran some experiments
back in 1982 and found that entrance pupils for our
members ran the gamut from 5mm on up to about 8mm -- in
general decreasing with age.  I'm 47 now and my entrance
pupil is only about 5mm, even in very dark conditions.


-------- REPLY, End of original message --------

You know the exit pupilis too large when the shadow of the diagonal exceeds
the size of your eye pupil!  Then you don't see anything at all!