Re: [delmarvastargazers] Re: clear aperture reflector
I agree also. I just stop down my 13.1" Coulter to get some pretty good
planetary images. Better yet, come to the Mirror Making Class and make a
set of Schiefspiegler 4.25" optics that a few of us with be making. Bill
Cheng will have his completed 'scope there and one look through it with
show you how excellent it is on the planets, moon and double stars.
02/28/2005 08:15 cc
[delmarvastargazers] Re: clear
Please respond to aperture reflector
Doug and all,
I agree thisi s a niche scope. IF yougot money to blow the ngo for it
if you want another scope in your collection. Itmight be very good
for planetary and lunar imaging and viewing but you can get just as
good views with other scopes that are more versitile.
For example, my 12.5" F5 Dob has aexcellent mirror butrarely can iuse
it on the planets at full apeture due to poor seeing. A apeture mask
hough that allows on a 3.5 inch apeture centre off the secondry and
focuse and bettwenthe spider vanes allows me to havea 3.5 inch clear
apeture at F17.8.
Doug will tell you how good this can be :)
To boot i still have a large dob too.
--- In firstname.lastname@example.org, "Norton Douglas \(DTI\)"
> Sky & Tel has a review of the scope in the April issue. There was alot of debate about who this scope is for. Very simply, for those who
want to observe the moon, bright planets and double stars and nothing
else (save maybe the sun) with the ultimate contrast, no color
fringing and no obstruction. It is considerably cheaper than a high
quality refractor of equal aperture (just look at those Tele Vue's!)
and in the review it outperformed a $4,000 Questar. So this is a
niche scope for a very specific type of observing. I am not defending
the small aperture or the price. But understand someone out there has
a use for this scope which performed superbly in the Sky & Tel review.
>much larger in diameter than the primary mirror, this is how the
> Douglas A. Norton
> Department of Technology & Information
> William Penn Data Center
> Phone: 302-739-9604
> Fax: 302-677-7003
> Email: Douglas.Norton@s...
> From: Michael P. Borgia [mailto:mborgia@c...]
> Sent: Sat 2/26/2005 9:09 PM
> To: email@example.com
> Subject: Re: [delmarvastargazers] clear aperture reflector
> What is interesting about the design is that the optical tube is
secondary housing is able to reside outside the light path. The
other unusual feature of this particular telescope is that it is of
unusually long focal length. At F 13.6, it would be very frustrating
to do any astrophotography with it. The telescope also weighs in at
48.8 pounds fully assembled, which is heavier than a fully assembled
C-8 or many larger Dobsonians. Just not worth the price or work for
a 3.6 inch telescope. Give me the aperture with the central
obstruction any day.
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