Product Review: Taurus Tracker III
Introduction
Anyone who has tried to get involved in the demanding field of astrophotography
or CCD imaging knows of all the various problems one can encounter.
The two that plagued me were focussing and centering of the object to
be imaged. Well, not any more! Enter the Taurus Tracker III by
Taurus Technologies, a device
designed to solve those very same problems. This "all-in-one" device
serves as a "flip mirror" for finding, centering and focussing objects
as well as acting as an off-axis guider.
The unit comes with:
- The Tracker III body.
- A Guide Port Extension to hold the buyer's choice of guiding equipment, be it
an ST-4 autoguider or an illuminated reticule eyepiece.
- A View Port Extension to hold the buyer's choice of eyepieces for
finding and focussing objects.
- A Telescope Adapter for attaching the T-3 to the telescope. Standards
include threaded adapters for common SCT's.
- A Camera Adapter for attaching the buyer's choice of CCD or film cameras.
- An extensive manual with instructions for the T-III's setup and use.
- A pair of vernier calipers for accurate focus calibration and measurement.
When I purchased the T-III, Taurus Technologies was very helpful
in determining the correct choice of equipment for my needs. Different
uses for the T-III can require different Extensions for the
guide and view ports, each a different length. I use primarily an
ST-4 autoguider and a Starlight Xpress MX-516 CCD imager. The MX-516
is mounted to an extension tube that places it at the same distance that
a regular film camera would reside, thus allowing me to get double the
use from all of my equipment. Taurus Technologies sent me the correct
assembly of adapters, and the rest is history.
It is recommended that the manual be read at least once thoroughly, and that
is good advice. I have had my share of trying to make various optical
components parfocal, so I knew what to expect. There were just a couple
of tidbits worth catching in the manual, and they help to make using the
T-III a joy. The vernier calipers allow one to make a precise measurement
of each port's distance from the tracker body. This allows one to
readily reposition the extension tubes should they ever change position.
Each port (guider/viewer) is a threaded extension with locking screws
to hold them in place. They also slide in and out in a sleeve, allowing their
attached mirrors to slide into and out of the guider body. The unit
itself is made of thick plastic. Do not let this bother you though. The
T-III is a professional piece of equipment and is much sturdier than
most of the off-axis and flip mirror units available today.
Here are some views of the unit attached to the back of a Celestron-8 SCT.
The first two Are without an imager attached. The third shows the
MX-5 CCD imager attached to the imaging port. In all three pictures,
the view port is in the "view" position with its slider mirror
intercepting the light cone from the telescope. Select an image for
a full sized view.
These next images are taken from the rear of the telescope looking into
the imaging port, the place where a camera or imager would normally be.
The first shows the tracker with the view port mirror in the "view"
position, thus blocking light from going to the imager. The second photo
shows the view port mirror raised out of the light path. The slider
is locked into position with a thumbscrew. The only thing you must
remember when imaging is to slide this view port mirror out of your
camera's light path, or you could image 20 minutes of darkness! I have
done this once already. Perhaps an improvement in later models
of the T-III will have an indicator or some such device to warn the
user.
Typical Steps for Deep Sky Imaging with the Tracker-III
The following are the typical steps one would go through to take an image
with the
Taurus Tracker III unit. All of these steps assume that the unit has been
callibrated, which is to say that the ports have all been made parfocal.
- Set up the telescope and mount. Polar align as usual.
- Assemble autoguider, computer, imager equipment.
- Attach the Tracker-III to the telescope with the four nylon screws
supplied. For an SCT, it mounts in place of the visual back.
A lock ring first attatches to the threaded end of the OTA and
is locked down with a set screw. The T-III body then attatches to this
ring with four nylon set screws. By slightly loosening these screws,the
T-III unit can be rotated to allow for guide star aquisition.
- Insert a high power eyepiece into the view port of the Tracker-III.
Be sure to slide the port into the optical path of the OTA.
- Focus on a relatively dim star. For an 8" SCT at f/6.3, this would be
a magnitude 12 star. Be sure to use your glasses if you normally use
them for distance vision. Do not touch the telescope's focus knob after
this point.
- Locate the object you wish to image. Center it within the viewport.
- Insert a low power eyepiece into the guide port of the T-III. Loosen the four
lock screws of the Tracker-III and rotate it while looking for a guidestar.
Center the guidestar and replace the eyepiece with your favorite guiding eyepiece
or autoguider.
- Slide out the view port and lock it in the retracted position.
- Start guiding.
- Start your image integration or astrophoto.
~John A. Blackwell
Last Modified: 3/19/03 8:55p
This page:© Copyright 2005 by John A. Blackwell
