
October 1st 03, 04:47 AM
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Upgrade from 60mm to 90mm
Thanks for the reply... and the warning.
--
Dan Braasch
"Alan W. Craft" wrote in message
...
On Tue, 30 Sep 2003 19:55:33 -0500, "Scutter"
....reflected:
I have a 60mm Bushnell refractor from 1991 (Japanese optics). I have the
possibility to buy a used Meade 90mm F/9(?) refractor OTA for $150 (not
the
ETX types, a full size refractor). I have read that above100mm false
color
becomes more pronounced with standard achromatic scopes, and I cannot
afford
the ED or apo scope. A 90mm also won't overload the mount I have the 60mm
on
at this time. So I figure 90mm is as large as I'll go until budget
allows. I
want a refractor in this case, not a reflector. (I have a small newtonian
as
well, so I am familiar with them.)
Question: I know I am doubling the lens area, so I should be able to see
a
bit more. Is the difference in aperture from 60mm to 90mm going to be
worth
it?
I went from a 60mm refractor to an 80mm...BIG difference, so yes,
it will be worth it; but by all means start-test it, for ten years ago I
bought
a Meade 90mm achromat on an alt-az mount, and the optics were
dreadful, even after Astronomics replaced it with another.
It may or may not be the same telescope; nevertheless...caveat emptor.
I have read that a 90mm refractor is a decent scope. Moon and planets
are my main interests, but I do like to look at the stars, too.
Before you buy, look at those stars hard, and out-of-focus on both
sides, too; bon chance!
Any replies would be appreciated.
Alan
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