Criterion Dynamax 8? Need some advice.
Glen Ilacqua
local reputable telescope dealers. I had originally come in looking for a
5-6" newtonian on an equitorial mount - or something of the sort. Then in the
corner of the showroom was a very nicely maintained older 8" SCT on a
motorized wedge EQ mount and substantial, and nicely preserved older tripod.
The shop owner told me it was a Criterion Dynamax 8, and that an older
customer had traded it in on a GOTO mounted scope.
The dealer said that the optics were in excellent condition and that the
previous owner really cared for the scope. Since I hadn't done any research
on this type of scope (out of my price range) I had no idea what it was. But
I was really excited at the prospect of being able to get such a large,
tracking scope. The dealer has a 10 day cash refund policy and a 30 store
credit policy, and since I had driven an hour and a half to get there, I
bought it for $500. Quickly set it up at home in my back yard just to see if
I could get a sense of the optics. After fumbling with the polar alignment
(and allowing it to cool for an hour) for the first time I looked at a few
things and was not all that impressed. I then found that the primary mirror
was totally frosted over with dew.
I packed everything up and came inside. I figured I'd do a little research on
the scope and to my horror, found that this model has a reputation for being
really terrible. I have only a few days to decide to return it, so I am
wondering if anyone has any advice to help me decide if I've bought a lemon
or not. In reading postings to a few web sites, there are a few people who
said they have a "good" one and have been using them happily for decades. How
do i figure it out before I run out of time on the return policy? SInce this
is my first scope, I'm a little confused about what to do.
Any advice is appreciated.
Glen
Mike
The first one was so bad I sent it back to Criterion, thinking I had
received a 'lemon'. They sent a replacement that, supposedly, was
"hand-picked" for quality. It sucked too!
That was over 30 years ago. In all that time I have NEVER met, spoken
with or read a posting from ANYONE who had a Dynamax 8 and liked it.
There MUST be SOMEONE out there that got a good one - but I've never
found him/her!
Hope this helps....
Mike Harvey
fcat...@msn.com
Frank
Tucson
nytecam
Any advice is appreciated.
Glen
I've got a 6" Criterion SCT gathering dust in the corner right now.
Bought a decade and a half ago for a few £/$ and image poor - ok for
looking at the moon at low power - and through patio doors didn't make
the image worse!
However got my money's worth when I converted it into a nice spectroscope
- see http://home.freeuk.com/m.gavin/ebert.htm
Nytecam
51N 0.1W
--
nytecam
starburst
> While shopping for a simple first scope, I went to one of the only (semi)
> local reputable telescope dealers. I had originally come in looking for a
> Any advice is appreciated.
>
> Glen
>
Glen, I've gotta agree with the others here - take it back. It might be
OK, but the odds are against you and you won't be able to find out if
the optics are good until you have a night of unusually good seeing and
the ability to judge the seeing and the optics, and that takes
experience. I'd like to look through one of these old dynamax's just to
see if they're as bad as the reputation. But for a first scope and 500
beans you can buy much safer equipment.
Take it back, get your money, do your homework, and then buy something
nicer.
Chris
Gil
Glen Ilacqua
style padded case, so I could potentially even ship it to you. It has all of
the electronics for the motor, a Telrad, the original finder scope, the legs
for table-top use and the Golden Pyramid mount and field tripod. All of it is
in very nice shape considering it's age. The scope's serial number is 4190.
I have a company with a UPS account and would be willing to ship it at my UPS
rate too. I am planning to return it to the dealer tomorrow. So if you are
interested, call me today at 781-264-3449.
Glen
On Tue, 4 Oct 2005 09:59:17 -0400, Gil wrote
(in article <1128434357....@g49g2000cwa.googlegroups.com>):
> I might want to take the scope off your hands. Where are you located?
>
On Tue, 4 Oct 2005 09:59:17 -0400, Gil wrote
(in article <1128434357....@g49g2000cwa.googlegroups.com>):
RMOLLISE
Glen Ilacqua wrote:
> While shopping for a simple first scope, I went to one of the only (semi)
> local reputable telescope dealers. I had originally come in looking for a
> 5-6" newtonian on an equitorial mount - or something of the sort. Then in the
> corner of the showroom was a very nicely maintained older 8" SCT on a
> motorized wedge EQ mount and substantial, and nicely preserved older tripod.
> The shop owner told me it was a Criterion Dynamax 8, and that an older
> customer had traded it in on a GOTO mounted scope.
>
>
Hi:
Bottom line? One of the worst telescopes I've ever seen. I have never
seen a Criterion SCT that's better than barely average...and those
_that good_ are few. What's ronic is that Criterion's Newtonians
(e.g.,the RV-6) were some of the best scopes made in the 60s - 70s (for
the price, at least).
If you want more gory details, see the Dynamax section of my (free)
Used SCT Guide at <http://skywatch.brainiac.com/astroland/index.htm>.
Peace,
Rod Mollise
Author of _Choosing and Using a Schmidt Cassegrain Telescope_
Like SCTs and MCTs?
Join the SCT User Mailing List.
<http://www.groups.yahoo.com/group/sct-user>
See my home page at
<http://skywatch.brainiac.com/astroland/index.htm>
for further info
For Uncle Rod's Astro Blog See:
<http://journals.aol.com/rmollise/UncleRodsAstroBlog/>
RMOLLISE
Glen Ilacqua wrote:
> While shopping for a simple first scope, I went to one of the only (semi)
> local reputable telescope dealers. I had originally come in looking for a
> 5-6" newtonian on an equitorial mount - or something of the sort. Then in the
> corner of the showroom was a very nicely maintained older 8" SCT on a
> motorized wedge EQ mount and substantial, and nicely preserved older tripod.
> The shop owner told me it was a Criterion Dynamax 8, and that an older
> customer had traded it in on a GOTO mounted scope.
>
>
Hi:
John Savard
part:
>That was over 30 years ago. In all that time I have NEVER met, spoken
>with or read a posting from ANYONE who had a Dynamax 8 and liked it.
>There MUST be SOMEONE out there that got a good one - but I've never
>found him/her!
I have their *four* inch Schmidt-Cassegrain, and it seems to be OK.
I'm sorry to hear this about the 8-inch one.
John Savard
http://home.ecn.ab.ca/~jsavard/index.html
http://www.quadibloc.com/index.html
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Dah_Rainbow_Mob
Dah_Rainbow_Mob
S y z y g y
I had two of these back in the early '70s. The first was so
bad Criterion took it back. The second one was sort of
acceptable and I kept it for a couple years but as I learned
more I understood that scope was pretty bad too.
I'd say return it.
- Bill
"Glen Ilacqua" <g_il...@yahoo.com> wrote in message
news:0001HW.BF676E45...@news.rcn.com...
Glen Ilacqua
River's Camera for being very cool about it and honoring their 10 day no
questions asked return policy. But I just had to print out a few pages from
Rod Mollise's book on SCTs and give it to the guy at the dealership when I
returned the scope. We had a good talk and I'll probably buy some more stuff
there when I need to.
Thanks to all for the feedback.
Glen
On Mon, 3 Oct 2005 23:24:53 -0400, Glen Ilacqua wrote
(in article <0001HW.BF676E45...@news.rcn.com>):
Larry Stedman
Has the company ever put out a high quality telescope? One that wasn't
plagued by design and quality control problems?
Larry Stedman
Vestal
Marty
and had settled on an 8 inch SCT, I had brochures from Celestron and
Criterion sitting beside by chair for months. My final decision was
based on the fact that I saw plenty of pics of people using Celestrons
in Sky & Telescope, but no Criterion Dynamax's. I still feel lucky!
Marty
joni...@aol.com
plagued by design and quality control problems?
Larry Stedman
Vestal
--------
I think the short answer is that YES, for many years Criterion made
some nice scopes.
Here's the long answer...
Criterion first made Newtonians, probably the most common of them is
the RV-6. Even though these were made from about 1958 until the late
70's, many of them are still providing pinpoint images across the field
of view.
I have recently acquired two of them, one I have used quite
extensively and have been very impressed with the optics as well as the
over all design. Optically it seems to be very good, the central
obstruction is moderate at about 22%, I believe the mirror is Pyrex and
well figured, it cools down quickly with a nice open aluminum mirror
cell. At low magnifications it provides views that a pinpoint sharp
and refractor bright from edge to edge, at high magnifications it does
the same. I am sure these scopes are part of the reason that 6 inh F8
Newtonians have a reputation as "Planet Killers."
I like the old style EQ mount, the clutch on the RA drive means I
don't have to keep fooling with the locks as one does on a Polaris
mount. It is simple to use, it's enough to seduce a DOB guy. The
composite tube means that the entire OTA only weighs 8 lbs.
>From what I have read on the net and from exchanges with other owners,
these scopes have a reputation for have very good optics. In fact
there is a post in this thread commenting:
" I bought one around 1973 or 74 and gave up on it after observing
with a friend's RV-6."
At the time they were made, these were "big scopes" for most amateurs
and I believe the "dream scope" of many, even though they sold for $200
in 1960. Of course $200 had some meaning in 1960.
----------
Criterion also made an 8 inch scope and an 4.5 incher and probably
others as well.
They made good Newtonians that provided nice views, (RV is supposed to
stand for Real Value).
When they tried to get into the SCT business, well that was their
downfall. Celestron understood how to make an reasonably priced SCT
and Criterion was out of their league.
But the mere fact that I have two RV-6's that are essentially original
and still giving the good views and tracking like they shouldis
testiment to the fact that at one time Criterion made some high quality
equipment.
Given the mechanical and electronic complexity and likely obsolence of
many of today scopes, probably those mounts will be dead and gone while
the old Criterion AC drives are still alive and kicking and providing
those same 6 inch F8 Newtonian views.
I am sure some folks here were around when these first hit the scene
and can give a better description.
Best wishes, clear skies
That's my two cents....
jon isaacs
Rich
Same thing with me in 1978. The wrong decision could have been
a disaster.
-Rich
Dah_Rainbow_Mob
joni...@aol.com
Still are... <G>
jon
Gil
1979 until 1985. Dynamax's were OK, the one I built for myself was
outstanding. Too bad I sold it when I was young and foolish!
RV-6 was my second scope. I previously owned a 4-1/4 f/10 Edmund EQ
reflector. Dynamax was next, have had a bunch of different scopes since
then. Hey, that makes me want to start a new thread.
Larry Stedman
reflector line was by them... they were even reviewed favorably by
Consumer Reports of all things years ago.
I own a nice small guidebook by a reporter called something like summer
star gazing or some such and even discusses the RV-6 in the back! I
guess they simply couldn't figure out to do an SCT.
And what was Asimov thinking, eh?
Larry Stedman
Vestal
joni...@aol.com
reflector line was by them... they were even reviewed favorably by
Consumer Reports of all things years ago
Yes and it is quite sad they decided to try to make DynaMax SCTs. If
they had stuck with what they could do well, maybe they would still be
around today making some nice, simple newtonians with quite good optics
at a reasonable price.
As a side note...
The other day I saw a Dynamax 8 inch SCT advertised on a local "for
sale board." The seller wanted $300 and pointed out that the corrector
plate was broken but that this was a "simple repair."
I posted a cautionary "re--" ad warning potential purchasers that
finding a corrector plate for this scope would be difficult...
Jon