| |
 |
|
|
Science Forum Index » Astro - Amateur Forum » Nebie Query
Page 1 of 1
|
| Author |
Message |
| TRIK3R |
 Posted: Wed Feb 14, 2007 4:32 am |
|
|
|
Guest
|
After a few months using a Meade ETX 80 AT goto scope, I feel like I'd
like something more "stick shift". I've been looking at the Orion
Maksutovs [90/100] at the $300+ level. Are they fairly decent? Money is
not an object, but I'm not sure of my commitment level.
Would also like a recommendation for a vendor. A lot of the on-line
stores seem to have the same Minnesota address.
TIA
Trik3r
Remove the obvious from my return address.
-- |
|
|
| Back to top |
|
| Larry G. |
| Posted: Wed Feb 14, 2007 7:58 am |
|
|
|
Guest
|
On Wed, 14 Feb 2007 02:32:32 -0600, TRIK3R <TRIK3Rspamless@GMAIL.COM>
wrote:
Quote: After a few months using a Meade ETX 80 AT goto scope, I feel like I'd
like something more "stick shift". I've been looking at the Orion
Maksutovs [90/100] at the $300+ level. Are they fairly decent? Money is
not an object, but I'm not sure of my commitment level.
Would also like a recommendation for a vendor. A lot of the on-line
stores seem to have the same Minnesota address.
TIA
Trik3r
As a general rule, "next" telescopes are a major shift away
from what is already owned. Going from an 80mm, to 90 or 100
mm, doesn't seems like there would be much to be gained.
If you want to make a quantum jump in terms of what you can
and will see, consider getting an 8" dobsonian telescope.
It's about as "stick shift" as you can get, with vastly
greater light gathering power, resolution and useable
magnification.
As for vendor, I've always had good luck with Astronomics.
http://www.astronomics.com/
Cheers,
Larry G.
--
Your mind is a terrible thing to waste - TURN OFF YOUR TV!
----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
|
|
| Back to top |
|
| Joe S. |
| Posted: Wed Feb 14, 2007 8:36 am |
|
|
|
Guest
|
"TRIK3R" <TRIK3Rspamless@GMAIL.COM> wrote in message
news:gaednbmuDqK9VE_YnZ2dnUVZ_h3inZ2d@comcast.com...
Quote: After a few months using a Meade ETX 80 AT goto scope, I feel like I'd
like something more "stick shift". I've been looking at the Orion
Maksutovs [90/100] at the $300+ level. Are they fairly decent? Money is
not an object, but I'm not sure of my commitment level.
Would also like a recommendation for a vendor. A lot of the on-line
stores seem to have the same Minnesota address.
TIA
Trik3r
Remove the obvious from my return address.
--
Probably not a good idea to go from an 80mm scope to a 90- or 100mm scope
because you will not gain anything in terms of magnification or
light-gathering.
If you have a scope and want to add a second scope, it's best to add a
second scope that is quite different from your present scope. You have a
small GO-TO scope that's adequate for "grab-and-go" or "quick look"
situations, so, your second scope should have quite a bit more aperture --
8-inches or more. On the other hand, if you already have a big scope -- 8-,
10-, 16-incher -- then you probably need a small scope -- 80-, 90-, or 100mm
for quick looks.
My recommendation is that now you need a much bigger scope. A bigger scope
will open up a lot more viewing for you. However, bigger scopes cost more
than smaller scopes (in general). If money is no object and you want a
GO-TO scope, go for one of the big Schmitt-Cass scopes in 8-inch, 10-inch,
or larger aperture. These are good, solid scopes -- but -- setup takes some
time -- polar alignment, setup counterbalance weights, etc. -- and you can
sink over $1,500 without even trying.
Another option is a Dobsonian reflector -- a Dob. You can get an 8-inch
Orion XT-8 for under $400; XT-10 under $600; and XT-12 (a BIG sucker) for
under $900. If you add the Orion Intelliscope function, add $250 for the
Intelliscope base and controller. The Intelliscope IS NOT a GO-TO
system -- the Intelliscopes are NOT motorized. You use the handheld
computer to align the scope then the computer tells you to move the scope
up/down, right/left to find the object.
As a general rule, Dobs provide more aperture per $ than any other scope.
For example -- an 8-inch Dob (203mm) has 6.4 times the aperture of your 80mm
scope -- that means objects will be brighter and many objects that you can't
even see in the 80mm -- such as faint, fuzzy deep sky objects -- will be
readily visible in the 8-incher.
Another factor is highest magnification. With the 80mm scope, your highest
theoretical magnification is around 192X -- with an 8-inch scope, your
highest theoretical mag is 480X. In practical use, 250X is about all you'll
want to use but your 80mm scope can't even come close to this.
Here is my experience, for what it's worth:
http://www.schlatter.org/Dad/Astronomy/my%20scopes.htm |
|
|
| Back to top |
|
| Davoud |
| Posted: Wed Feb 14, 2007 11:59 am |
|
|
|
Guest
|
TRIK3R:
Quote: After a few months using a Meade ETX 80 AT goto scope, I feel like I'd
like something more "stick shift". I've been looking at the Orion
Maksutovs [90/100]
Larry G.:
Quote: If you want to make a quantum jump in terms of what you can
and will see, consider getting an 8" dobsonian telescope.
A /quantum/ jump? Wouldn't that mean a jump from an 80mm 'scope to an
80mm + 10e-33 meter scope? Doesn't seem like much of a leap to me...
:-=
Davoud
--
usenet *at* davidillig dawt com |
|
|
| Back to top |
|
| Chris L Peterson |
| Posted: Wed Feb 14, 2007 12:12 pm |
|
|
|
Guest
|
On Wed, 14 Feb 2007 02:32:32 -0600, TRIK3R <TRIK3Rspamless@GMAIL.COM>
wrote:
Quote: After a few months using a Meade ETX 80 AT goto scope, I feel like I'd
like something more "stick shift". I've been looking at the Orion
Maksutovs [90/100] at the $300+ level. Are they fairly decent? Money is
not an object, but I'm not sure of my commitment level.
You should consider more aperture- something like an 8", 10", or 12"
Dob. And a Dob would seem to fit nicely with your "stick shift" concept.
Quote: Would also like a recommendation for a vendor. A lot of the on-line
stores seem to have the same Minnesota address.
I'd stick with Orion- especially for somebody still getting their feet
wet in astronomy. Orion Dobs are very nice, and a great value.
_________________________________________________
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com |
|
|
| Back to top |
|
| Llanzlan Klazmon the 15th |
| Posted: Thu Feb 15, 2007 6:27 pm |
|
|
|
Guest
|
TRIK3R <TRIK3Rspamless@GMAIL.COM> wrote in
news:gaednbmuDqK9VE_YnZ2dnUVZ_h3inZ2d@comcast.com:
Quote: After a few months using a Meade ETX 80 AT goto scope, I feel like I'd
like something more "stick shift". I've been looking at the Orion
Maksutovs [90/100] at the $300+ level. Are they fairly decent? Money is
not an object, but I'm not sure of my commitment level.
The little Meade is a good grab and go scope but unless you are planning to
get into astro-photography, get a big dob as your next scope (at least as
big as is convenient for you to move around etc). That gets you into a
whole new territory of what you can actually see. I would go for a 200mm
aperture as bare minimum for you next scope but recommend 300mm plus unless
the bulk size factor causes you a problem.
Bill
Quote:
Would also like a recommendation for a vendor. A lot of the on-line
stores seem to have the same Minnesota address.
TIA
Trik3r
Remove the obvious from my return address. |
|
|
| Back to top |
|
| AstroApp |
| Posted: Mon Feb 19, 2007 4:11 pm |
|
|
|
Guest
|
On Wed, 14 Feb 2007 16:12:05 GMT, Chris L Peterson
<clp@alumni.caltech.edu> wrote:
Quote: On Wed, 14 Feb 2007 02:32:32 -0600, TRIK3R <TRIK3Rspamless@GMAIL.COM
wrote:
After a few months using a Meade ETX 80 AT goto scope, I feel like I'd
like something more "stick shift". I've been looking at the Orion
Maksutovs [90/100] at the $300+ level. Are they fairly decent? Money is
not an object, but I'm not sure of my commitment level.
You should consider more aperture- something like an 8", 10", or 12"
Dob. And a Dob would seem to fit nicely with your "stick shift" concept.
I'd stick with Orion- especially for somebody still getting their feet
wet in astronomy. Orion Dobs are very nice, and a great value.
Chris L Peterson
Yes: very apt suggestions.
But also to the OP: you will be surprised at how much brighter things
look with a 2-mirror Newtonian, than with a 3-mirror compound
telescope (utlizing a star diagonal), as there is less light loss (and
the lower price entrance-level equipment almost never has state of the
art high reflectance coatings on the mirrors, or high quality
lowest-loss multicoatings on the lens surfaces.) You could get a
significant improvement in what you see by going from a compound
telescope+star diagonal to a simple Newtonian of even the same
aperture (though no one is likely ever to recommend a Newtonian of
90mm aperture!)
To answer your questions about the Orion Maks: they are good
instruments but not great ones, in my experience. When in
collimation, a 102 or 127 Orion Mak will give fairly decent deep sky
views above, say, 50x or so. At the highest power, for planetary use,
they are sometimes a bit soft or show flare, due to collimation
errors. The collimation system on those scopes is very rudimentary,
and in my experience it is not stable over time. I worked for many
hours adjusting a friend's scope so that the planets were fairly sharp
without a significant flare around the planetary disk caused by
miscollimation. Then, the scope did not stay that way for very long.
Collimation is achieved by adjusting the pressure of screws that tilt
a back plate; but the rear of the telescope tube assembly, holding the
collimation screws, is held on by the differential pressure of other
screws against a large o-ring (which can collapse, irregularly, if the
pressure is high, changing the collimation.)
But, if you go with a Newtonian scope having a shorter focal length
and lower focal ratio, you can easily reduce the magnification and
increase the field of view for the larger diameter (and consequently
fainter, lower surface brightness) celestial objects. Large open star
clusters will be more nicely appreciated in a wide field. The Orion
127 Mak can only look at the central region of the Pleiades, for
instance; with a f/4.5 to f/8 scope, you can see the whole cluster
with 'room to spare'. The lower magnification provided by such scopes
will allow you to effectively use nebular filters, too. f/12 to f/15
scopes will always provide such small exit pupils with a standard
range of eyepieces that often nebular filters are ineffectual and make
everything too dim.
So consider not only a change in aperture, but also one of focal
ratio. If you move up to a 6 or 8 inch telescope with a lower focal
ratio, you will have an ENTIRELY different kind of instrument that has
a very different kind of optimal use: much more of a "deep sky scope"
than a typical high focal ratio, small aperture compound telescope.
The trade-off, though, will be that "fast" short focal ratio Newtonian
scopes will have coma distortion on star images, and won't yield as
nicely clean and pinpoint stars at their lower powers, unless you buy
expensive specialized eyepieces. Every scope has its limitations and
its virtues. Newtonians such as I describe perhaps will not have as
elegantly clean stars away from the center of the eyepiece field, but
will give you much more light gathering and show far fainter objects.
So, your Meade ETX telescope will still have very different optical
qualities that might be more suitable for certain types of astronomy
(such as enjoying double stars within the resolution range of the
aperture.) The wider your interest becomes in the variety of
celestial objects, the more you may enjoy having different types of
telescopes.
AstroApp |
|
|
| Back to top |
|
| Starlord |
| Posted: Mon Feb 19, 2007 5:16 pm |
|
|
|
Guest
|
|
| Back to top |
|
| |
|
Page 1 of 1
All times are GMT - 5 Hours
The time now is Fri Oct 10, 2008 6:56 pm
|
|