QSI WSG 500 Series User manual

500 Series WSG
User Guide
Revision 1.2
August, 2009
Disclaimer:
The specifications in this document are subject to change without notice.
All trademarks mentioned in this document are the property of their respective owners,
and are used herein for informational purposes only.
2007-2009 Quantum Scientific Imaging
Phone 888-QSI-4CCD • www.QSImaging.com

Table of Contents
1. GETTING STARTED
Guiding Fundamentals 4
5
6
7
7
8
9
10
11
15
16
17
21
22
22
22
22
23
23
24
25
26
27
Get to Know the WSG Cover
Integrated Guider Port Components
Main and Guide Camera FOV
Compatible Guide Cameras
2. FEATURES & OPERATION
Setting up the WSG
Attaching a Guide Camera
Attach the camera to your telescope
Focusing the Guide Camera
Filter Thickness and the IGP
3. GUIDING
Autoguider support in MaxIm LE
Using an AutoGuider
Guider Control Port
4. ACCESSORIES
T-mount adapter plate
2” nosepiece for T-mount
2.156” adapter plate
2” nosepiece for 2.156" adapter
C-mount Guide Camera Adapter
T-mount Guide Camera adapter
5. CARE & MAINTENANCE
Removing the WSG cover
Technical support
APPENDICES
Appendix A –WSG Specifications
Appendix B – Warranty

Sectio
n
1
Getting Started
Thank you for your purchase of a QSI 500 Series WSG model camera.
The QSI 500 Series WSG models are an innovative new addition to the QSI 500 Series family
of cooled CCD cameras. The WSG has an internal mechanical shutter and filter wheel like the
500 Series "ws" models, plus it adds an Integrated Guider Port (IGP). The Integrated Guider
Port allows guiding using the light from your main telescope while picking off the light from the
guide star in front of the filters.
QSI 532wsg Shown with 2.156” Faceplate Adapter and
T-mount Guide Camera Adapter
This WSG User Guide is a supplement to the QSI 500 Series User Guide. Please refer to the
full user guide for complete details about operating and caring for your QSI camera.
If you’re upgrading your current QSI 500 Series camera to a WSG model, please see Section
5, Care and Maintenance for instruction on how to replace your current camera cover with the
new WSG cover.

Guiding Fundamentals
Several options exist for guiding long-exposure images of the night sky. The Integrated Guider
Port in the QSI 500 Series WSG works by redirecting a portion of the light from your main
telescope with a pick-off prism into a separate guide camera mounted on top of the WSG
cover.
The Integrated Guider Port solves a number of the problems associated with other common
guiding solutions. In the image above the red arrows represent the portion of the light
redirected to the guide camera. The light enters the camera, strikes the pick-off prism
positioned in front of the built-in 5-position color filter wheel and is reflected upward at 90
degree angle into the guide camera attached on top.
By picking off the light for guiding from in front of the filters and mechanical shutter, you’re able
to utilize all the light from your guide star for guiding. No light is lost by first passing through a
red, green, blue or narrowband filter, guaranteeing the highest possible signal to noise ratio
(SNR) for your guide stars. You can guide even while the shutter is closed.
The large ½" square pick-off prism is optimally positioned close to the internal filter wheel just
outside the field of view of the main sensor, supporting the use of guide cameras with large
sensors, while preventing any vignetting of the main sensor even with very fast optical
systems.
4

Get to Know the WSG Cover
Take a few minutes to familiarize yourself with the
major features of the WSG cover.
The images above show the major features of the cover for a QSI 500 Series WSG model
camera. The pick-off prism shown in the two bottom images will not interfere with the filters in
the internal color filter wheel.
Understanding how the QSI WSG cover is designed and built will allow you to use it in the
most effective way. Examine the photos above to gain an understanding of how the parts of
the WSG cover and Integrated Guider Port (IGP) work together.
Tools you’ll need (included with QSI cameras):
0.050” Allen Wrench - Focus Ring and Guide Camera Adapter set screws
3/32” ball-end Allen Wrench - Attaching or removing WSG cover
5

6
Integrated Guider Port Components
The image to the right shows the guide camera
Focus Base exposed on top of the WSG Cover.
The Focus Base has outside threads with 32
threads per inch (tpi) allowing very precise and
stable guide camera focus.
In the image to the left, the guide camera
Focus Ring has been threaded onto the Focus
Base. The Focus Ring provides roughly 3mm
of travel for focusing the guide camera. After
achieving focus, the Focus Ring is locked into
position with a set screw accessed through a
slot in the WSG Cover. The Focus Ring has a
V-groove that allows the C-Mount or T-mou
Guide Camera adapter to be locked into
position with three set screws after rotating the
guide camera to the desire
nt
d orientation.
place, the C-mount or T-
mount Guide Camera Adapter can be placed
o the right, the C-mount Guide
Camera adapter is being placed onto the IGP
See Section 2, WSG Features and Operation
for details on focusing the guide camera.
With the Focus Ring in
over the Focus Ring.
In the image t
focus ring.
IGP Focus Base
IGP Focus Ring
Guide Camera Adapter

Main and Guide Camera Field of View
Guide camera sensor position relative to main sensor
The image above shows the size and effective position of the pick-off prism and guide camera
sensor in relation to the main sensor in a QSI 500 Series WSG model camera. The center of
the pick-off prism (and effective position of the guide camera sensor) is 0.675” (≈17mm)
above the optical axis of the telescope and the center of the main sensor.
Compatible Guide Cameras
The WSG cover is designed for guide cameras that have a maximum back focus of 12.5mm.
Many general purpose cameras and dedicated guide cameras are designed with 12.5mm of
back focus to fit the CS-Mount specification, which uses the same thread as C-mount (1” x
32tpi) but with 12.5mm of back focus instead of the C-mount standard of 17.5mm.
The camera you select for your guide camera does not need to have guider outputs. Widely
used astronomical image acquisition programs can be configured to send the guider correction
signal through the guider out port on QSI 500 Series cameras. With MaxIm DL or LE, this is
done by configuring the guider correction signals to be sent through the “Main Relays”.
At the time of publication, the following guide cameras are known to be compatible with the
WSG. See this web page for the most current list: http://store.qsimaging.com/kb.asp?ID=13
Starlight Express Lodestar C-mount
Meade DSI Pro I, II, III T-mount (Requires 3r
d
party low profile adapter)
Orion Starshoot Autoguider T-mount
Orion Starshoot Imager II T-mount
The Imaging Source Cameras C-mount
7

WSG Cover Features and Operation
Setting up the WSG
A WSG model camera can be attached to your telescope in a variety of ways. The image
above shows the camera with the optional 2.156” x 24tpi faceplate adapter. Your camera may
be configured with a T-mount faceplate adapter (42mm x 0.75mm). 3rd-party adapters and
accessories are widely available for both faceplate thread specifications. A threaded
nosepiece designed to slide into a standard 2” eyepiece adapter is also available from QSI for
either faceplate adapter. See Section 4 for a complete list of accessories.
Note: The large diameter faceplate adapter uses 2.156” x 24tpi threads. The T-
Mount adapter uses industry standard 42mm diameter x 0.75mm pitch threads.
Always make certain that any device you attempt to thread into either adapter has
proper matching threads. Some optical components have threads that may appear
similar, but have slightly different dimensions. Never force-thread anything
into a threaded adapter.
Section
2
8

9
Attaching a Guide Camera
Guide cameras attach to the WSG cover using a
C-mount or T-mount Guide Camera Adapter. The
image at the right shows the C-mount Guide Camera
adapter being placed over the IGP Focus Ring.
A WSG model camera will come configured with either
the C-mount or T-mount guide camera adapter already
attached.
Note: The WSG cover is designed for guide cameras that have a maximum back
focus of 12.5mm. Many general purpose cameras and dedicated guide cameras
are designed with 12.5mm of back focus to fit the CS-Mount specification. CS-
Mount uses the same thread as C-mount (1” x 32tpi) but with 12.5mm of back
focus instead of the C-mount standard of 17.5mm.
The picture at left shows the T-mount Guide
Camera Adapter attached to a Meade DSI Pro
(with the optional, 3rd party low-profile T-mount
adapter) being lowered onto the Focus Ring.
As shown in this picture, you may find it easier
to thread the C-mount or T-mount Guide
Camera adapter onto the front of your guide
camara and then place the adapter and guide
camera onto the IGP Focus Ring.
Using a 0.050” Allen wrench (included with QSI 500 Series cameras), tighten the 3 set screws
around the perimeter of the Guide Camera adapter to lock the guide camera to the Focus Ring

Warning: After placing a guide camera on the Focus Ring make sure the Guide
Camera adapter is fully seated on the Focus Ring and that one or more of the
three set screws are sufficiently tightened to prevent the guide camera from
Falling. While focusing the guide camera, you’ll want to loosen the set screws and
keep one hand on the guide camera.
Attach the camera to your telescope
Attach the QSI 500 Series WSG camera and guider combination to your telescope. The
method you use to attach the camera to your particular telescope will vary depending on the
telescope and choice of adapters. Make sure all threaded adapters are firmly screwed in to
the front of the camera, and tighten any retaining screws to ensure the camera is stable and
will not slip or move when the orientation of the telescope changes.
Attach power and USB cables to the QSI and guider cameras and connect to the camera with
your image acquisition software. Refer to the QSI 500 Series User Guide for details on how to
attach cables to the camera and connect to it with your software
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Focusing the Guide Camera
Plan to spend a few minutes getting the guide camera focus correct the first time you use the
camera. After achieving good focus with the guide camera you should rarely, if ever, have to
adjust the guide camera focus again, even if you remove the guide camera and put it back on
the WSG at a later time.
Focusing the guide camera is straightforward, although the required steps may be a bit
different than you’re used to. There are a couple different ways to handle focusing the guide
camera. We have found the steps below to work best for most people.
Note: Always start by focusing the image on the camera’s main sensor using your
telescope focuser and standard focusing method. Only after your primary
imaging camera is focused should you attempt to focus the guide camera.
Loosen the Focus Ring Set Screw by inserting a 0.050” Allen wrench (included with QSI 500
Series cameras) into the set screw through the small opening near the top of the cover.
Rotate the Focus Ring to the left or right to change the focus of the guide camera.
Note: The guide camera Focus Ring is threaded with 32 threads per inch
(tpi). This allows very precise and stable focusing. When trying to achieve
rough focus, rotate the Focus Ring at least one full turn and possibly more.
One full turn will change the focus by only 1/32” (0.031”) or 0.8mm.
Rotate the Focus Ring clockwise to reduce the guide camera focus distance
Rotate counter-clockwise to increase the guide camera focus distance.
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Enter “Focus Mode” with the Guide Camera
Make sure your guide camera is attached to the focuser on the Integrated Guider Port and any
required cables are attached. If you have not already done so, connect to the guide camera
with your image acquisition software.
Setup your software in “Focus Mode” to take images continuously. Set the exposure long
enough so that you can see good stars with a high signal to noise ratio in the guide camera
image . In the example below the exposure length is set to 1 second. You may need to adjust
the exposure time in the “Seconds” field up or down in order to capture a few bright stars
without saturating. Setting the exposure time fairly short allows you take more focus images in
a shorter period of time, generally allowing you to achieve sharp focus fairly quickly.
Note: Critical focus is not as important for the guide camera as it is for your main
imaging camera. Some guiding experts even recommend defocusing the guide
stars just a bit as that produces a smoother distribution of light about the position
of the star. The slightly defocused image can reduce the effects of “seeing”
allowing a more accurate “center of mass” calculation of the guide star resulting in
smoother guiding.
Because the guide camera sees all the light from the stars in the guide camera field of view,
you should be able to find one or more stars suitable for focusing (or guiding) wherever you
happen to be pointing. Refer to Section 1, Field of View, for details on the portion of the sky
viewed by the guide camera relative to the main image sensor.
In MaxIm LE, select View > Camera Control Window, then click the Focus tab. Click “Guider”
to focus the guider. The example below shows binning set to 1. Setting binning to 2 may work
well for focusing the guide camera. Click the checkbox next to “Continuous” to take images
repeatedly with the guide camera. Click “Start Focus”.
Examine the images returned by your image acquisition program. As stars come into focus
they produce a smaller disk of light with more of the total light from the star being focused into
a smaller area. The total size of stars in your guide camera images will vary depending on the
focal length of your telescope, the size of the pixels in your guide camera and your local seeing
conditions.
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There are a number of techniques used to determine when an image is in focus. A common
technique is to calculate the Full-Width Half Maximum (FWHM) of the star. The FWHM of a
star will get smaller the closer it is to critical focus. Here’s a MaxIm screenshot showing two
images of the same field of view. The image on the right is closer to focus than the image on
the left
Note the two yellow highlighted fields in the Information Window. In the Autoguider image to
the right, the maximum pixel value inside the blue rings has a count of 3380. The FWHM is
1.817 pixels. In the out of focus image to the left, the values (not shown) are a maximum of
910 counts and FWHM of 4.655 pixels. The total amount of light recorded from the star is the
same, but the energy is spread out over more pixels in the out of focus image.
Note: The Inspect tab next to the Focus tab can help you achieve focus by
analyzing the area around the brightest point light source in an image. Review the
MaxIm LE online help for additional details about focusing.
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Focus the Guide Camera
The Focus Ring set screw should be loosened allowing the Focus Ring to be rotated. Loosen
the 3 set screws on the Guide Camera Adapter so you can lift the guide camera free from the
Focus Ring. Leave the guide camera adapter threaded to your guide camera. Hold onto the
guide camera so it doesn’t drop.
With your software capturing images continuously in Focus mode, lift the guide camera off the
Focus ring, rotate the Focus ring (at least one full turn to start), and then place the guide
camera back down on the Focus ring. Examine the images and FWHM to determine if you’re
getting closer or further away from correct focus.
Repeat the steps below until you’ve achieved good focus with the guide camera:
1. Lift the guide camera off the Focus Ring
2. Rotate the Focus Ring to adjust focus
3. Place the guide camera back on the Focus Ring and hold it in place while
checking the images for correct focus
When you’re happy with the guide camera focus, tighten the Focus Ring set screw to lock the
focus into place.
Rotate the guide camera to the correct orientation and lock it into place by tightening the 3 set
screws around the perimeter of the Guide Camera adapter.
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Filter Thickness and the Integrated Guider Port
The Integrated Guider Port on the WSG cover is designed to bring the guide camera image to
focus at the same focal depth as the main sensor. Adding additional glass to an optical path,
such as the glass in a filter, reduces the effective focus position by roughly 1/3 the thickness of
the glass. For instance, adding a 3mm thick filter will reduce the optical back focus by
approximately 1mm.
No two filters are exactly the same thickness, but in most situations, the small variations in filter
thickness will not require refocusing the guide camera. Because the pick-off prism is
positioned in front of the filter wheel, the focus position of the guide camera will not change
when filters of different thicknesses are positioned in front of the main sensor, however the
focus of the main sensor will change slightly. If changing a filter requires adjusting the
focus on your telescope, you may also want to refocus the guide camera. Note however, as
mentioned earlier in this section, guiding works very well even if when the guide stars are
slightly out of focus.
Note: It’s best to use filters that are all approximately the same thickness with the
WSG. Once the guide camera has been focused with a filter in the path to the
main sensor, the guide camera focus will not require adjustment when changing
filters. In practical terms, it is usually best to standardize on filters from one
manufacturer as they will usually be made from the same glass substrate.
Other sources of small changes in focus should not require adjusting the guide camera focus.
Once you’ve focused your guide camera, the guide camera sensor will be positioned at the
same focal depth as the main sensor. For instance, If changes in temperature require you to
refocus your telescope, adjusting the focus on the main sensor will automatically bring the
guide camera to the correct focus position as well.
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Sectio
n
3
Guiding
Note: This section is repeated from the QSI 500 Series User Guide.
The QSI 500 Series camera can be used as you main imaging camera or as an autoguider.
MaxIm LE supports the following cameras as autoguiders. Other camera control software,
such as MaxIm DL support additional autoguiders with a QSI camera.
Autoguider support in MaxIm LE
Meade DSI Pro, DSI Pro II, DSI Pro III Any recent SBIG camera
Orion StarShoot Video DirectShow
Orion StarShoot Autoguider Lumenera
Starlight Express Lodestar
Fishcamp Starfish Any QSI camera
QSI 500 Series cameras have a Guider port on the bottom of the camera. This port sends
guider correcting signals to your telescope mount. Connect the included guider cable from the
camera Guider port to the AutoGuider port on your telescope mount. The guider correction
signals output by the QSI 500 will work with most modern telescope mounts using the included
guider cable.
The photo to the left shows the guider
cable connected to the AutoGuider
port on a Losmandy Gemini System.
Please refer to your camera and
mount specifications to confirm your
mount is compatible with the signals
from the QSI 500 Series camera. QSI
offers an optional Guider Break-Out
Box (GBOB) for connecting to older or
non-standard mounts. Please see the
QSI web site for complete details.
16

Using an AutoGuider
This section provides basic instructions on how to use your QSI 500 Series camera as your
main imaging camera and set up a separate camera on a guide scope for guiding. For this
example, we’re using a Meade DSI Pro as the autoguider. For complete instructions on
guiding, including a step-by-step tutorial, please see the Online help in MaxIm LE.
Setup your QSI 500 Series camera as described above. Hook up your guider camera to your
guide scope and connect the guider camera to your computer.
Go to the Setup tab of the Camera Control window. Click the Setup button in the Autoguider
panel.
Follow the instructions that came with your autoguider camera to enable and configure the
camera. Click OK to return to the Setup tab of Camera Control Window. Click Connect. If
your cameras are hooked up and configured correctly, the status panels for each camera will
show the current status of your main CCD camera and your Autoguider.
17

Click the “Guide” tab to the left of the Setup tab. The Start button will be enabled if the
autoguider camera was setup correctly.
Click the black arrowhead to the right of “Options” below the Stop button and select “Guider
Settings.”
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In the guider settings window, make sure that “Main Relays” is selected in the “Control Via”
pop-up list under Autoguider Output. This instructs MaxIm to send the autoguider control
signals through the Guider port on the QSI 500 Series camera. If your autoguider camera also
has a guider port, you can select “Guider Relays” to send the signals through the autoguider
camera. MaxIm supports additional methods of generating the correct control signals. See
the online help in MaxIm LE for complete details. Click OK to close the Guider Settings
window and return to the Guide tab of the Camera Control Window.
You may need to focus your guide scope. You can take an image with your guide camera by
pressing the Start button. Set the exposure only as long as necessary to still yield well-defined
stars. Shorter exposures allow quicker cycles between guiding exposures and smoother
guiding.
The first time you press Start with a new exposure length, MaxIm LE will automatically take a
dark frame. Follow the instructions on screen. Press Start as necessary to take additional
images while focusing your guide scope. Stop when you are satisfied with the focus and
exposure length.
19

MaxIm LE automatically selects the brightest star as the guide star.
You are now set up for guiding. Continue with instructions in the online help in MaxIm LE to
calibrate your autoguider and begin tracking the selected guide star.
Note: For complete instructions on guiding, including a step-by-step tutorial,
please refer to the “Autoguiding” section of the Online help in MaxIm LE.
20