34
35
7. The
ASCOM Telescope Chooser
(Figure 25) will appear. Select your
telescope model from the provided
choices. If your model does not
appear, it is not supported by the
ASCOM platform.
8. After you have selected your tele-
scope model, click the
Properties
button.
9. In the window that pops-up,
choose your specific
Scope Type
and desired
Serial Port
where the
computer will send commands to
the mount. Click OK when done.
10. Click
OK
in the
ASCOM Telescope Chooser
window.
11. In the
Settings
window, click the
Close
button.
Some telescope mounts, such as the Orion Atlas EQ-G and Sirius EQ-G, uti-
lize an “ST-4 compatible” autoguider jack. For easiest autoguiding with these
mounts, we recommend purchasing the optional USB Guide Port interface
(GPUSB). This adapter box will translate the autoguiding computer commands
from MaxIm DL Essentials into ST-4 pulse commands. The GPUSB connects
to the computer’s USB port instead of the COM port. A cable then connects
the GPUSB to the mount. In addition to installing the ASCOM platform on your
computer (from the
Install ASCOM
button in the
Launcher
), you will need
to install the GPUSB ASCOM driver (downloadable from the Orion website,
www.OrionTelescopes.com). Then, you can select the GPUSB in the
ASCOM
Telescope Chooser
.
Other telescope mounts accept commands in the “LX200 Protocol”. For these
mounts, it is not necessary to install the ASCOM platform to have the com-
puter “talk” to the mount. To setup the autoguider for mounts that use the
LX200 Protocol:
1. Connect the StarShoot Pro to your computer and open the Maxim DL
Essentials software.
2. In the
Camera Control Window
, click on the
Guide
tab.
3. Click on the
Settings
button.
4. In the window that pops-up, select
LX200 Protocol
for the
Autoguider
Output Control Via
. Select the
COM Port
of the computer you would like
to use to send commands to the telescope
5. Click the
Apply
button, then click the
Close
button.
autoguider Calibration
In order to properly control the mount, you must calibrate the system. The
exact orientation of the StarShoot Pro, the focal length of the guide telescope
optics, and the speed of the motor drive all affect the calibration. To perform
autoguider calibration:
1. Switch to the
Guide
tab.
2. Set the
X
and
Y Aggr
(aggressiveness) to 8 to start with. Set the
Exposure
to 1.0 second. Under
Guide Star
, make sure the
Watch
box is checked.
Note: The
X
and
Y Aggr
(aggressiveness) controls on the Guide tab allows
you to adjust how vigorously star motions are tracked out in each axis. An
aggressiveness setting of 10 means that the StarShoot Pro attempts to track
out 100% of the motion, whereas a setting of 1 means that the StarShoot Pro
only tracks out 10% of the motion. Usually a setting of around 8 or 9 provides
the best tracking, since it reduces overshoot and helps ignore random motions
due to atmospheric seeing and wind loads. You should experiment to deter-
mine the best setting for your particular telescope.
3. Click the
Settings
button.
4. Maxim DL Essentials needs to know how fast the telescope moves in right
ascension (R.A.) and declination (Dec.) when the autoguider commands
are issued. To do this, the software will
Calibrate
the mount by moving it
back and forth on each axis. The
Calibration
Time determines how long it
activates the motors each time. The usual value is 5-10 seconds; start out
with a value of 5.
5. Make sure all of the
Guider Enables
boxes are checked.
6. For
Autoguider Output
, set
Control Via
and
COM Port
as required for
your telescope equipment. See “Computer to Mount Connection” if you
have not already done this.
7. Click
Apply
. You can leave this dialog box open, or
Close
it if you wish.
8. Make sure that the telescope mount is set to move at 1X sidereal or slower.
For some mounts, you must set the guide rate manually. The maximum
usable rate is 1X sidereal. If your mount does not drift quickly, then 0.1X is
recommended; otherwise use a value between 1X and 0.1X.
9. On the
Guide
tab, set to
Expose
, and click the
Start
button. A single
image will be taken. Ensure that a well-focused bright star (near the actual
object to be imaged) appears in the image. If not, adjust the guide scope
and try again. Make sure the star is roughly centered.
Note: The algorithm can be confused if another star appears in the frame; to
minimize this risk, calibrate on an isolated bright star.
10. Now, set to
Calibrate
, and click the
Start
button. A series of five expo-
sures will be taken; each time the telescope will be moved slightly. If the
Figure 25.
The
ASCOM Telescope
Chooser
provides an easy way
to establish a computer-to-mount
communications link if the mount is
supported by the ASCOM platform.
