I have used many of the Chinese made refractors sold
by Orion finding the 90mm with the 910mm focal length the most useful
for my seeing
conditions and ease of use requirement.
One missing capability of the 90mm was it could not
use 2 inch eyepieces and I wanted to try out a higher quality objective.
type scopes were beyond what I could spend on this hobby I purchased
the Stellarvue 80/9D for $399. I bought the 2002 version. The 2003
version is $449 and the key difference is that the 2003 version
the retracting dew shield where mine does not. At the time of this
writing Stellarvue is still selling the 2002 version. No eyepieces
or diagonal comes with this OTA.
The Stellarvue 80/9D is an 80mm (3.1
inch) achromatic scope with a 750mm focal length for a f/9.4 focal
ratio. I have it mounted on
an Orion AZ-3 altazimuth mount. I’ve done a review on this
mount here on Cloudy Nights and you can find it under the review
for mounts section.
The scope does come with a red dot finder but
I prefer a right angle, correct view, 50mm viewfinder. The right
angle provides more comfort
when searching for objects and the 50mm allows me to find many of
the Messier objects that are my favorites and are within the capability
of this scope like M42, the Orion Nebula. Note: I had to file down,
significantly, the Orion 50mm finder base to get it to fit into the
Stellarvue’s dove tail mount. So, if you do not own a 50mm
finder and decide to buy one for this scope you may want to buy Stellarvue’s
instead of one from Orion.
The dew shield on the Stellarvue is longer
than most. In one evening my finder fogged but my objective remained
fog free through the night.
With other scopes I’ve owned if my finder fogged so did my
Colorful double stars have become a passion for me
in the last few months. I like them because when the Deep Sky Objects
washed out by the haze or a light layer of clouds, which happens
often here in North Carolina during the Summer, I can often still
view my growing list of favorite double stars. Also, for small scope
users this is about the only chance to see color and nice color contrast.
found on the Chinese made 90mm refractor scope that pushing it to
60 times its objective diameter in power (212X) degrades the image
except on the Moon. On double stars that are close together, say
2.5 seconds apart, this kind of power will introduce a diffraction
ring around the primary that hides the secondary.
I have pushed the
Stellarvue to 202X (65 times the diameter) on Izar (in Bootes) and
there is a slight and very thin diffraction ring
around part of the primary but the secondary outshines the diffraction
ring and is clearly seen. I’ve used about 180X power on the
Double Double in Lyra with no diffraction rings noticed. Also, on
Rasalgethi, in Hercules at 150X and no diffraction rings were noticed.
other advantage is the ability to use 2 inch eyepieces. With a 40mm,
2 inch Plossl, with 62 degree field of view
I get about 3 degrees field of view through the Stellarvue to sweep
the Milky Way; very nice. If the 90mm could use 2 inch eyepieces
with its 910mm focal length it would get about 2.5 degrees field
Accessories that I am using with the Stellarvue which
I am happy with are:(prices are as of 30 August 2003 and do not
include shipping and handling; just for reference)
Stellarvue’s 1.25 inch deluxe diagonal.($49)
Meade 2 inch diagonal bought from Surplus Shed .($30)
Shorty-Plus, 1.25”, 2X Barlow.($70)
standard, 1.25”, zoom (22 to
7.4mm). ($50) This zoom does accept
Apogee’s deluxe, 1.25” zoom
(23 to 7mm) ($60) This
is a good zoom optically for the price But
wore off showing
the focal length
in the first few weeks of owning and it
will not accept filters.
2 inch Plossl.($149)
Stellarvue’s 26mm 2 inch Plossl.($69)
40mm 1.25 inch Plossl.($49)
Orion’s 1.25 inch 6mm
Explorer II eyepiece.($28)
1.25 inch 5mm Orthoscopic
In conclusion, is the extra money I paid for the Stellarvue worth
it? Yes, especially since my interest in double stars is growing
and that it works very well with the AZ-3 mount. Also, cool down
time is nil and its light weight allows me to move it about to avoid
trees, street lights and other obstacles. Please, feel free to email
me with any questions.
Note: I have posted in the Small Scope and Double Star forums here
on Cloudy Nights an office 2000 excel file listing sort able data
on about 50 colorful, double stars and most are within reach of a
3.1 inch refractor. If you are a member you can download it.