SKY-WATCHER SynGuider II User Manual

SYNGUIDER Ⅱ USER'S MANUAL

GETTING STARTED

3

1

4

9

15

060613V1

Thank you for choosing the SynGuider. The
SynGuider can guide an equatorial mount
without the help of a computer. It will
improve the image quality and help you
achieve pin-point stars in you long-exposure
photography.

BASIC OPERATIONS

OPERATION UNDER THE NIGHT SKY

SPECIFICATIONS

PREPARING THE SYNGUIDER

ABOUT THE SYNGUIDER II PACKAGE

SynGuider’s Main Body

Par Focal Ring

Hand Pad Guiding Cable Battery Case

M42-to1.25 Adapter

1.25” Extension Barrel

1

Please take some time to check your new SynGuider II package and become familiar
with each component. Some parts are installed on the SynGuider main body out of
the box. You will need to uninstall them before using the SynGuider.

SYNGUIDER II MAIN BODY

A

FRONT VIEW

REAR VIEW

B

CD E F

2

G

A. M42 thread B. Image Sensor C. Power Jack D. USB Port
E. Autoguider Port F. Hand Pad Port G. LCD Screen

PREPARING THE SYNGUIDER

3

PREPARING THE POWER SUPPLY

User can use four D type 1.5V batteries (not included) with the battery case as the power
supply for SynGuider. To use a different power supply, it must match the following require­ments:

DC 4.5V~14V output voltage, a +5V power supply is recommended.
150mA and up output current

2.1mm power plug, central positive

PREPARING THE IMAGING SYSTEM

The basic requirements for the equipment to use with SynGuider are:

Telescope Mount: Equatorial mount, or Alt-Az mount with a
wedge, with a dual-axis motor drive attached. The motor drive
must be able to accept “ST-4” compatible autoguiding signals.
Connecting Cable: You may use the supplied dual RJ-12 plug
autoguiding cable if the pin configuration of your motor drive is
the same as the diagram shown on the right. An alternative cable
is required if the pin configuration of your motor drive is different.
Guide Scope: An additional telescope with a M42-0.75 thread or a 1.25” eyepiece holder is
required as guide scope. Larger aperture, at least 80mm, helps reduce the exposure time of
the SynGuide, thus yielding more accurate guiding result. The ideal focal length is between
400mm and 1200mm. An adjustable guide scope tube ring and a finderscope or red dot finder
are recommended for searching for a guide star.

654321

1= NC
2= Ground
3= +RA (left)
4= +DEC (up)
5= -DEC (down)
6= -RA (right)

BASIC OPERATIONS

4

It is highly recommended that you familiarize yourself with the basic operations of the SynGuider
indoors before going out under the dark sky.

Option 1: The SynGuider can be threaded onto a telescope with a M42 thread adapter. Gener­ally, this installation method provides the most secure connection. It is best suited for the guide
scope equipped with a finderscope or a red dot finder.
Option 2: Install the M42-to-1.25 adapter to the main body of the autoguider, and then insert and
lock the autoguider into the 1.25 inch eyepiece holder on the guide scope. This installation
method is suitable for using a par-focal eyepiece to search for a guide star due to its convenience
in exchanging the SynGuider for an eyepiece.

ATTACHING SYNGUIDER TO A GUIDE SCOPE

There are two ways to install the SynGuider on a guide scope:

CONNECTING CABLES

Plug the hand pad into the 8 pin RJ-45 connector on the main body of the autoguider.
Plug one end of the guiding cable into the autoguider port on the autoguider and the other end
into the equatorial mount. Plug in the battery case or the power supply of your choice.

READING THE LCD DISPLAY

The LCD display is divided into two zones. The left half of the LCD screen displays text informa­tion, such as the menu, data and the status of the device. The right half of the LCD screen displays
the image captured by the optical sensor. In the screen, stars are represented by dots.

BASIC OPERATIONS

5

USING THE HAND CONTROL

There are nine illuminated buttons on the hand pad:

Menu: Used to open up the main menu.
ESC: Used to cancel an operation or quit from the menu.
Enter: Used to enter a submenu or confirm an operation.
+: Used to increase the exposure time.

-: Used to decrease the exposure time.
Up/Down buttons: The function of these buttons depends on the

working mode of the autoguider:

Left/Right buttons: The function of these buttons depends on the working mode of the autoguider:

Preview Mode: Manually toggle the Dec+ and Dec- signal of
the ST-4 autoguider port.
Menu Mode: Scroll between the menu items.
Data Input Mode: Change the parameters.
“Manually Lock Guider Star” Mode: Move the small pick-up
crosshair vertically.
Guiding Mode: Set the Dec correction aggressiveness.

Preview Mode: manually toggle the RA+ and RA- signal of the ST-4 autoguider interface.
Menu Mode: The right button is to enter a submenu. The left button is to confirm a menu
operation. It performs as the Enter button.
Data Input Mode: The left button is to confirm a menu operation. It performs as the Enter button.
“Manually Lock Guider Star” Mode: Move the small pick-up crosshair horizontally.
Guiding Mode: Set the RA correction aggressiveness.

MENU

ESC

ENTER

BASIC OPERATIONS

6

OPERATING THE MENUS

Press the Menu button to activate the main menu tree. Use the UP or DOWN buttons to scroll
through the menu items. Press the ENTER or the RIGHT button to choose between the following
submenus:

LOCK Menu: This submenu is used to lock a star in SynGuider’s field of view (FOV) for later
guiding operation. After entering this submenu, use UP or DOWN button to choose from the
following options and then press ENTER or LEFT button to confirm:

ZM STAR or ZM CTR. Menu: These two menus are usable only when the SynGuider is working
under the preview mode. It is used to zoom in on the image. Using the UP/DOWN buttons,
choose between the zoom level 1 (the entier image), 2 (384X384 pixels of the image sensor), 3
(128X128 pixels of the image sensor) and 4 (64X64 pixels of the image sensor). After choosing
the level, press ENTER to confrim or ESC to keep the previous zoom level.
"ZM STAR" tries to use the position of the brightest star in the FOV of the SynGuider as the
center of the zoomed image, unless the star is too close to the edge of the image sensor. "ZM
CTR." always zooms at the center of the image sensor.

AUTO: the SynGuider will try to automatically lock the brightest star in the FOV.
MANUAL: the SynGuider will show a small pick-up crosshair in the image area of the LCD
display, where you can use the four direction buttons to move the crosshair onto or near a star.
Press ENTER to lock the SynGuider on the star.
UNLOCK: allow the SynGuider to exit from the locked mode or guiding mode and return to the
preview mode

Look to the upper left corner of the LCD display to find out which mode the
SynGuider is currently working under.



BASIC OPERATIONS

7

GUIDE Menu: This menu is used to activate or de-activate autoguiding. Use the UP/DOWN button
to choose from the following three options:

AUTO CAL: The SynGuider will start an auto-calibration routine prior to the start of autoguiding.
RESUME: The SynGuider will immediately start autoguiding with the previous guiding parameters.
STOP: The SynGuider will stop autoguiding and return to the locked mode.

CROSS Menu: This menu is used to turn on the crosshair on the LCD screen.
DEC BACKLASH Menu: To reduce the influence of Dec axis’ backlash during autoguiding, the

SynGuider can send a Dec+ or Dec- control for a pre-determined time when the SynGuider
changes the polarity of the Dec control signal. Once this menu is selected, you will see the current
setting displayed in the text zone of the LCD screen. Use UP/DOWN buttons to change the value.
Press ENTER or LEFT button to confirm. If your equatorial mount has no or minimal backlash, or if
you have done very accurate polar alignment, the Dec backlash should be set to 0.

NOISE Menu: This menu is used to set the cut-off value for the noise filter of the image sensor.
The proper noise level differs from exposure time, thus the SynGuider provide independent noise
level setting for each exposure time and will automatically use the corresponding nosie level when
the user change the exposure time.
Once this submenu is selected, you will see the current cut-off value displayed in the text zone of
the LCD, while the image zone of the LCD keeps refreshing.

If there is a short solid horizontal line shown in the upper or middle portion of the LCD's image
area, it means that the cut-off value is too low and you should increase it until you can see
reasonable amount of noise dots diversify evenly in the LCD's image area.

BASIC OPERATIONS

8

RESET Menu: This menu resets all the settings back to the factory default settings.

If there is no noise spot appear in the image zone of the LCD, it might mean that the cut-off
value is set too high and this might reduce the sensitivity of the SynGuider for detecting faint
stars. You should reduce the cut-off value until you can see some noise dots diversify evenly in
the image area.

9

OPERATING UNDER THE NIGHT SKY

The key steps of operating the SynGuider are:

The following sections explains the practical operations of the SynGuider:

ADJUST FOCUS (PREVIEW MODE)

The SynGuider enters the PREVIEW mode as soon as the power is turned on. Following is an
example of what you will see.

Step 1: Adjust the focus (PREVIEW mode)
Step 2: Align the SynGuider with the mount (Very important. Do not skip)
Step 3: Find and lock a guide star (LOCKED mode)
Step 4: Start autoguiding (GUIDING mode)

PREVIEW
EXP 100
BRI 35
X 105
Y 68
ZOOM 1
X0 0
Y0 0

The left half of the LCD screen
displays text information.

The current mode

The right half of the screen
displays the image detected
by the sensor.

The current exposure
The brightness of the brightest star

The position of the brightest star

The current zoom level

The position of the center of the
image window in the sensor’s pixel
matrix

Stars are represented
by dots.

The brightest star is
framed.

10

Follow these steps to adjust the focus of the guide scope:

1). Insert an optical eyepiece into the eyepiece holder of the guide scope. Activate tracking of the
mount. Center a bright star in the eyepiece’s field of view.

2). Remove the optical eyepiece and replace it with the SynGuider.

3). Use the “+” or “-” buttons on the hand pad to set the exposure time to 100 milliseconds.

4). Use the NOISE Menu to set the noise control level until the LCD is free of background noise.

5). Adjust the focuser of the guide scope until the image of the bright star appears in the LCD as a
blank dot. Continue to adjust the focuser until the the blank dot appears to be smallest, suggesting
that the image is in focus. At this point, if you continue to turn the focuser you will see that the dot
becomes larger again. The BRI reading will increase as the image comes into focus. If the BRI
reading increases to over 100, use the “-” button to reduce the exposure time to avoid
over-exposure. If the BRI reading still keeps high with minimum exposure, try to use a fainter star
for focusing.

6). Use the "ZM STAR" menu to change the zoom level to show more details of the star image.
Fine tune the focuser to obtain the smallest star image and the highest BRI reading. Lock the
focuser of the guide scope and remove the SynGuider from the guide scope.

7). Now it is the time to make a par-focal eyepiece for later use. A par-focal eyepiece can be used
to locate the guide star, or to adjust the focus of the guider scope for subsequently setting up the
guider scope.

Follow these steps to make a par-focal eyepiece:

OPERATING UNDER THE NIGHT SKY

OPERATING UNDER THE NIGHT SKY

11

1). Loosen the locking screw on the par-focal ring. Insert an
optical eyepiece into the eyepiece holder through the par-focal
ring, as shown on the right.

2). Slowly move the eyepiece in and out of the eyepiece
holder until the image of the star is the sharpest. Keep the
eyepiece still with one hand, and firmly push the par-focal ring
against the eyepiece holder with one finger, while tightening the
locking screw on the par-focal ring with the other.

3). The par-focal ring should be firmly attached to the eyepiece.
You may remove the eyepiece from the guide scope now.

ALIGN SYNGUIDER WITH MOUNT

Follow these steps to align the orientation of the autoguider with the moving direction of the two
axes of the equatorial mount:

1). Turn on the crosshair on the LCD screen using the CROSS menu.

2). Adjust the autoguider so that when the equatorial mount is slowly slewing in RA axis the star
image moves parallel to either the horizontal or the vertical line. Instead of using the hand control
of the mount, you may also use the LEFT/RIGHT direction buttons on the SynGuider hand pad to
control the RA axis of the mount.

Attach the 1.25” extention barrel to the eyepiece if the eyepiece is too short to reach focus.



Remember or mark the position of the SynGuider on the guide scope so you won’t
have to perform the autoguider alignment again.



12

FINDING AND LOCKING A GUIDE STAR

1). Point the primary telescope to the target deep sky object (DSO). Activate tracking on the
equatorial mount. The guide scope should also be pointed to the same region in the sky.

2). Attach the par-focal eyepiece to the guide scope. Locate a brightest star nearby and adjust
the guide scope so the star appears in the center of the par-focal eyepiece’s FOV.

3). Replace the par-focal eyepiece with the SynGuider.

4). The image of the star should appear in the image zone of the LCD screen. If not, use the “+”
button to increase the exposure time until the image of the star appears. Use the NOISE menu
to filter out the noise if the image zone of the LCD screen becomes blank or too noisy..

5). Now is a good time to adjust the exposure time. Generally speaking, shorter exposure gives
better periodic error correction results. The BRI reading on the screen is a good reference. The
minimum BRI reading required for the SynGuider to work stably is 20. Try to bring the BRI
reading close to 20 for the best result.

6). Adjust the guide scope to bring the star to the center if it is too close to the edge of the image
zone on the SynGuider. This is only necessary when the ZOOM level is set at 1.

7). Lock the guide star automatically or manually using the LOCK menu.
If the guide star is successfully locked the SynGuider will enter the “LOCKED” mode. The

ZOOM level will automatically be switched to 4, and SynGuider will display an area of 64*64
pixels near the locked star.

OPERATING UNDER THE NIGHT SKY

LOCK:
EXP 50
BRI 40
DX 5.32
DY 4.38

X0 120
Y0 35

OPERATING UNDER THE NIGHT SKY

13

The diagram on the right is a example of the LCD display.
a) (DX, DY) are the locked star’s offset to its original
locked position.
b) (X0, Y0) are the position of the center of the image in
sensor’s pixel matrix.
c) If the SynGuider lost the guide-star, it will wait until the
star re-appears, or user can press the ESC button to
return to PREVIEW mode.

AUTOGUIDING (GUIDING MODE)

Once the SynGuider is successfully locked onto a star, you may active guiding with the GUIDE
menu.

Activate Autoguiding

AUTO CAL: This is recommended when the telescope has been moved to a new object. It will
start an auto-calibration routine to detect the correct setting of the guiding parameters, including
the polarity of the control signals and the guiding aggressiveness. SynGuider will automatically
start autoguiding after the calibration is finished successfully.

RESUME: This is to resume previous autoguiding. SynGuider will skip the auto-calibration
routine and start autoguiding with the previous guiding parameters.

14

OPERATING UNDER THE NIGHT SKY

GUIDING
EXP 300
BRI 25
GR 220
DG 180
DR -0.39
DD 0.25
RA+ Dec-

A crosshair is
displayed for you to
monitor the effects
of autoguiding. The
center of the cross
is the position of
the guide star when
guiding is activated.

Exposure time

The drift in R.A. and Dec. in pixels

Indication that the SynGuider is
sending RA+/RA- or Dec+/Dec­signals via the autoguider port.

R.A. and Dec. guiding
agressiveness in mS/Pixel

Operations

The guiding agressiveness of RA or Dec axis can be adjusted with the direction buttons on the
hand control. Use the RIGHT/LEFT buttons to increase/decrease the RA aggressiveness and the
UP/DOWN buttons to increase/decrease the Dec agressiveness. If the SynGuider losses the
guide-star during autoguiding, it will wait until the star re-appears, or user can press the ESC
button to return to PREVIEW mode.

Suspend Autoguiding

Use menu GUIDE/STOP to stop autoguiding. The exposure on the photographic camera should
be stopped before suspending autoguiding.

The following diagram is what you will see in the GUIDING mode.

Brightness of the star

SPECIFICATIONS

15

IMAGE SENSOR

Type: APTINA MT9V034C12STM CMOS Sensor
Chip size: 4.51mm(X) * 2.88 mm(Y)
Number of effective pixels: 752(X) * 480(Y)
Unit cell size: 6.0um(X) * 6.0um(Y)

POWER SUPPLY

DC 4.5V~14V, 150mA; a +5V power supply is recommended.
Power Jack: 2.1mm, tip positive; or USB type B

SENSITIVITY

Typically, the SynGuider II can capture and guide a star with up to the magnitude of 8.5 under the
following conditions: Regular 80mm aperture refractor, 500ms exposure time, and good seeing
conditions

EXPOSURE TIME

2, 5, 15, 30, 70, 100, 200, 300, 400, 500, 600 mS