http://www.skyandte ope.com.auo 65Vixen Polarie Star Tracker
astroshop.com.au • AUD$499
The sleek Polarie Star Tracker is a compact, rectangular drive that attaches
directly to your tripod with a ¼-20 threaded socket. Weighing just 680 grams,
it can handle cameras of up to 1.6 kg. The base model is aligned using a peep
sight to point toward the pople, which is accurate enough for exposures up to a
couple of minutes with a wide-angle lens. A built-in inclinometer (tiltmeter) helps
you accurately set the altitude adjustment. It can be operated in both Hemispheres
and offers sidereal, 0.5× sidereal, lunar and solar drive speeds. The unit is powered
using 2 AA batteries that last about 4 hours; it and can also be powered via a mini-
USB port.
Additional options for the Polarie include an unilluminated polar-alignment
scope, ball head, time-lapse adapter, and a Polar Fine Adjustment Unit that’s very
useful for exact altitude and azimuth adjustments. Vixen also offers a Polar Meter
with a built-in bubble level and altitude scale for daytime alignment (as when
shooting solar eclipses).
AstroTrac TT320X-AG
astrotrac.com • Starting at US$619
The AstroTrac is a futuristic-looking drive that doesn’t use a traditional
gear and worm drive. Instead, it uses a ‘worm rod’ that is actually a
section of screw with fine threads in a tangent arm that will track for 2
hours before the screw needs to be reset. The unit weighs 1 kg and can
carry a hefty payload of up to 15 kg. It operates in both the Northern and
Southern Hemispheres with sidereal, lunar and solar rates electronically
controlled for accuracy.
AstroTrac claims an unguided peak-to-peak tracking error of about 5
arcseconds over a 5-minute period. The TT320X-AG also has an ST-4-
compatible autoguider port for autoguiding in right ascension.
While the drive comes with a DC power cord, an 8-AA battery holder
is an additional option, as is an illuminated polar-alignment scope, a
ball head, and various accessories to make the drive into a complete
equatorial mount capable of bearing small telescopes with ease.
Fornax Mounts LighTrack II
fornaxmounts.com • Starting at about US$458This mount appears similar to the AstroTrac seen below, but it’s driven
using a flat-wheel friction drive with a claimed peak-to-peak drive error of 2
arcseconds over an 8-minute period. Like the AstroTrac, the drive needs to
be reset about every 2 hours. The LighTrack II weighs 1.3 kg and can carry 6
kg. It will operate in both the Northern and Southern Hemispheres at sidereal,
0.5× sidereal, lunar and solar rates. It also has an autoguider input for right
ascension corrections. The LighTrack II is powered via a 12V DC cigarette-
lighter cable. Additional accessories include a Sky-Watcher HM5 polar scope
and adapter thread and the FMW-200 adjustable wedge.