Sky and Telescope
refractor featuring a f/10 optical system with a 70mm lens
EQ-1 equatorial mount and aluminum tripod, 25mm and 10mm Explorer II
(Kellner eyepieces with 50 degree fields), 90 degree star diagonal,
EZ Finder reflex sight.
I always regretted giving away the 60mm
refractor that I owned as a kid. A gleaming white tube with uncoated
optics and dim, narrow views, it sat on a flimsy mount that never quite
locked the tube position where you needed it. I loved the thing,
despite the tiny eyepieces, wiggly Barlow, and scary sun filter. It became
a fixture in the corner of my room, always ready for an impromptu trip to
the back yard for half an hour of viewing.
When I returned to astronomy after many years, aperture fever gripped me.
I bought a 10" Dobsonian reflector. While it shows me lots of faint
fuzzies, nothing about it connotes “impromptu.” Carrying the thing
outside requires three trips for base, tube, and chair. Once planted,
forget moving the scope around the yard to dodge trees and lights. The
mirror needs a fair amount of time to cool down and the optics usually
require an alignment tweak. One also needs a strong back to use this kind
of telescope on a regular basis, and my finicky back dictated a smaller,
lighter telescope for regular use.
I pined for the ease and immediacy of a small refractor on an alt/az
mount. Setting myself a $200 limit, I bought a Bushnell Northstar 80mm
refractor (see review on this site). With a built in computer this scope
delivers a lot of bang for the buck. Negatives include substandard optics
(uncoated), a poorly-placed finder scope, low quality modified achromat
eyepieces, and a mount that proves difficult to handle at high powers.
I began looking at other small refractors below $200. Orion telescopes
listed a 70mm achromat model in their catalog that seemed well-equipped:
it came with a small equatorial mount, one included eyepiece, and a
probably worthless finderscope. At $159 it still looked like a bargain. I
ordered one just before Christmas and in January it arrived as promised,
in one box, evidently packed by a surgeon. Every piece came in a separate
inner box with protective bubble-wrap inside that.
The equatorial mount looked beefy for this small a scope. I assembled the
aluminum tripod with the provided tools, attached it to the mount, and set
it for alt/az mode. Small equatorial mounts make fine alt/az systems. Just
discard the declination axis (the screw-in pole) and counterweight, loosen
the latitude scale (the pivot at the base of the mount) and retighten it
after making the right ascension axis vertical. The right ascension axis
now becomes the azimuth pivot and the declination axis the altitude pivot.
This configuration gives you a low weight alt/az mount with both coarse
and fine movement (using the hand knobs on flexible stalks). It easily
holds a small scope without the need for a counterweight, plus it suspends
the scope’s tube slightly to one side of the mount, giving you the
clearance to view objects directly overhead. (The picture of the scope
shows the mount in this orientation.)
I bolted in the two metal tube rings (both with rubber linings to keep
from marring the scope’s finish) then attached the telescope itself.
When I opened the finder scope box I found, instead of the wimpy plastic
unit I expected, an actual EZ Finder II red dot reflex sight with a custom
mounting base. It attached easily, aligned easily, and even came with
fresh batteries installed. More surprises lay in store as I discovered
that the scope came with not one but two quite serviceable eyepieces (10mm
and 25mm), of a nice Kellner design (Orion actually sells them separately
as their Explorer II line). Another box contained a standard 1 & 1/4
inch mirror star diagonal.
A look down the telescope’s objective showed a well-coated, deep purple
lens free of reflections. The aluminum tube contains three spaced circular
metal baffles. Orion uses plastic for the lens shade and the focuser
housing, but metal for the focus mechanism itself.
I decided to run through the usual astronomical suspects for a small
telescope. Giving the scope the acid test for cool-down time, I carried it
from a 70 degree house to a 16 degree backyard. I pointed the red dot
finder at an object typically hard to resolve in a small scope, the
trapezium in Orion, then put in the 25mm eyepiece. Even at this
magnification (28x), I clearly made out four perfect points of light with
no trace of flaring (a sign of pinched optics). The tight focuser provided
enough range of movement to achieve crisp focus quickie, and the tripod
dampened vibrations in under one second. I popped in the 10mm eyepiece for
70X magnification. Still crisp and gorgeous. I then dipped into my other
eyepieces and tried an 8mm Plossl with a 2X Barlow for 175X. Even at 63X
per inch of aperture, the image remained crisp. I rate the optical quality
as truly outstanding for such an inexpensive instrument.
Next I tried a really big target, the Pleiades. The 25mm Kellner eyepiece
resolved the core nicely, but it took a 45mm Plossl to reveal all of the
cluster. With excellent seeing on such a calm, cold night, I slipped in an
Orion Ultrablock narrowband filter to look for nebulosity around the key
stars. Not a trace. Perhaps seeing it remains beyond the capabilities of a
70mm scope? Jupiter sat very low in the sky and the image boiled from
atmospheric turbulence, but Saturn winged high overhead, close to the full
moon. I pushed the power up to 175X again for grins, but decided that my
8mm eyepiece gave the sharpest view at 87X. Racking the focusser in and
out alternatively ringed the planet with faint green or faint violet, but
in focus the image remained free of spurious color. I think I made out the
Cassini division, but Saturn remains pretty small in a 70mm scope. I also
admit that the 16 degrees Fahrenheit air temperature prompted me to rush
things a bit.
Before my fingers went numb I panned around the full moon. The brilliant
white edge of the disc revealed no false color. While not an ideal phase
for observing, I pushed the power back up to 175X and panned around the
surface with the slow motion cables. The moon took high power very well,
and the cables gave me the precision to steadily move up and down the
of large craters with no vibration. I give the scope very high marks for
This scope needs a higher profile in Orion’s catalog!
The optics show little to no false color. The overall quality of the
optical system seems appropriate to a $500+ pseudo-apochromat. Orion
includes a first class mount and accessories. You wind up with a very
lightweight, very portable unit. Orion also includes a star chart current
for the month of delivery, plus a CD-ROM with a full-featured version of
Now my favorite telescope, this 70mm marvel puts spontaneity back into
star gazing. It transports me back to my parent’s back yard with my
first telescope. It leaps into my hands at the slightest encouragement: a
break in the clouds, a cancelled Boy Scout meeting, a squirrel on the back
fence. With zero cool-down time, no collimation hassles, and crisp
images, I call it the best bargain in small scopes today. Someday I plan
to send Televue about $5000 of my money, but for right now this little
scope gives me 90% of the apochromat experience at 1/30 of the cost!
Submitted by Scott T. Schad - firstname.lastname@example.org