Diffraction SBIG AFW Series User manual

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SBIG®AFW Series
Filter Wheel
User’s Manual
Version 1.02 - April 28, 2021

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This equipment has been tested and found to comply with the limits for a
Class A digital device, pursuant to part 15 of the FCC Rules. These limits are
designed to provide reasonable protection against harmful interference when
the equipment is operated in a commercial environment. This equipment
generates, uses, and can radiate radio frequency energy and, if not installed
and used in accordance with the instruction manual, may cause harmful
interference to radio communications. Operation of this equipment in a
residential area is likely to cause harmful interference in which case the user
will be required to correct the interference at his own expense.
Industry Canada Compliance Statement
This Class A digital apparatus complies with Canadian ICES-003.
European Union
This product has been tested and found to comply with the limits for Class A
Information Technology Equipment according to CISPR 22/European Standard
EN 55022. Warning: This equipment is compliant with Class A of CISPR 32. In
a residential environment this equipment may cause radio interference.
Visit us at:
http://diffractionlimited.com
and
http://forum.diffractionlimited.com/
Diffraction Limited
59 Grenfell Crescent, Unit B, Ottawa, ON Canada, K2G 0G3
Telephone: [phone]
Fax: [phone]
© 2020 Diffraction Limited. All rights reserved. Cyanogen Imaging®, SBIG®,
and Aluma® are registered trademarks of Diffraction Limited. Aluma AC, AFW,
StarChaser, SC-2, SC-3, ST-4, STF, STX, STXL, AO-X, MaxIm DL, and MaxIm
LT are trademarks of Diffraction Limited. Windows is a registered trademark of
Microsoft Corporation.
All other trademarks, service marks, and trade names appearing in this guide
are the property of their respective owners.

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SBIG Advanced Filter Wheel User’s Manual
Table of Contents
1 –The SBIG AFW Advanced Filter Wheels ....................................................... 4
2 –Supplied components.................................................................................. 5
3 –Installing the Filter Wheel ........................................................................... 6
Filter Installation........................................................................................... 6
Attach the Filter Wheel to the Camera ........................................................... 8
Final Assembly .............................................................................................. 9
Dual Wheel Assembly .................................................................................. 10
4 –Setting up the Filter Wheel........................................................................ 13
Single Filter Wheel....................................................................................... 13
Dual Filter Wheels....................................................................................... 14
DL Imaging –Aluma CCD, Aluma AC, STC Series ................................................................... 14
SBIG Universal –STX, STXL Series.......................................................................................... 17
5 –Specifications............................................................................................ 19

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1 –The SBIG AFW Advanced Filter Wheels
Diffraction Limited’ SBIG AFW series filter wheels are designed to consume the
minimum back focus distance while providing fast and quiet operation.
The AFW series wheels are designed to directly interface to all SBIG cameras
that utilize the “STX” style accessory mounting. This includes all Aluma AC
models as well as legacy STX and STXL models.
Currently two varieties are available:
•AFW-10-50SQ –ten slots accommodating 50 mm square filters, and
•AFW-12-50R –twelve slots accommodating 50 mm round filters.
A double-stack kit is available for all AFW wheels. This allows for two wheels to
be stacked, providing additional filter slots.
The AFW can be used with the StarChaser SC-3 SHORT, which provides self-
guiding in front of the filters. In conjunction with the StarChaser it is also
compatible with the SBIG AO-X adaptive optics unit.
All power and control signals for the wheel is provided by a single DB-9 style
connector, which connects directly to the main camera using the supplied
cable. No other connections are required.
Note: The DB-9 connector is not a serial port. It can only be connected to an
SBIG camera AUX connector.
The AFW design allows the filter wheel mounting screws to be accessed without
removing filters or the carousel. This makes installation and removal very
quick and easy.

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2 –Supplied components
Observe proper handling procedures for sensitive electronic equipment and
unpack your SBIG Advanced Filter Wheel and accessories carefully in a clean,
dry, static-free area. Inspect the contents to ensure all components are present
and in good order. You should find the following:
•AFW-10-50SQ or AFW-12-50R Filter Wheel
•DB-9 Male-Female cable, 2.5 foot
•6-32 x 5/16” Torx wrench
•5/64” Hex wrench
•1/16” Hex wrench
•Qty 2 –6-32 x 5/16” Torx flat-head screws
The included wrenches are used to install the filters and mount the filter wheel
onto the camera.
The DB-9 cable is a high-quality cable with large gauge wiring to provide
adequate power and control signals to the wheel.
Warning: Do not substitute a low-quality or longer cable as this will cause
control problems, including intermittent wheel operation.

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3 –Installing the Filter Wheel
Please follow these steps carefully to ensure correct installation.
Filter Installation
1. Lay the filter wheel down on a flat book or similar object so the protruding
screws and motor cover do not touch the tabletop.
2. Using the 5/64” Hex wrench, remove the 5 screws attaching the cover, and
set the cover aside.

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3. Each filter is retained by screws with fiber washers that help prevent
damage to the glass filter. Using the 1/16” Hex wrench, remove the screws
and washers for each slot.
CAUTION:
Be gentle! Apply only LIGHT vertical pressure to the retention
screws.
The filter carousel is intentionally very thin, to provide the minimum
possible impact on back focus distance.
If significant vertical pressure is applied to the screws, the carousel
may be warped, which could affect filter wheel operation.
4. Each filter slot will contain a plastic spacer. Remove the spacer, and set it
aside for now. The spacer is used when mounting thinner filters.
5. Install the filters in the slots, in the desired order (typical order is
Luminance, Red, Green, Blue, H-Alpha, S-II, O-III). The slots are labelled
starting at 1, which will match the slot numbers in your software.
6. Reinstall the spacers as follows:
•If your filters are 3 mm thick, do not install the spacer.
•If your filters are 2 mm thick, orient the spacer so the small cutouts align
with the washers. The cutout is 1 mm deep, so this effectively reduces
the thickness of the spacer to 1mm.
•If your filters are 1 mm thick, orient the spacer so the washers do not
align with the cutouts. You can flip the spacer over to do this.
7. Reinstall the fiber washers and retention screws. If you are using 2 mm
thick filters, make sure the washer nests into the cutout in the spacer.

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Attach the Filter Wheel to the Camera
The next step is to attach the wheel to the camera. The wheel base including
carousel, circuit board, and motor attaches directly to the camera. The lid of
the filter wheel will be facing the telescope.
Note: The DB-9 connector on the filter wheel is not a serial port. It can only be
connected to an SBIG camera AUX connector.
1. Ensure that the power into the camera is disconnected.
CAUTION:
Never “hot plug” cables into or from units. This is especially important
for the AUX connector. Always disconnect power before connecting or
disconnecting accessories or cables.
2. Remove the adapter plate from the front of the camera. Note the location of
any shim washers under the screws (the camera package should include a
“shim sheet” showing the shim locations, if any).
3. Remove any additional mounting screws from the front of the camera (some
have additional screws to accommodate different accessories).
Note: For the next series of steps, you will need two 6-32 x 3/8” Torx
flat head screws. They are included with the wheel in a small plastic
bag. There are also two identical screws already installed in the wheel;
they are captive under the carousel.
4. Note that two of the filter wheel mounting screws are under the carousel.
They can be accessed by rotating the carousel by hand to align the hole.
AFW filter wheel attached to an Aluma AC series camera

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5. Carefully position the filter wheel over the camera, so the two “captured”
screws that are under the carousel line up with the mounting holes on the
camera. Make sure the AUX connector is oriented close to the camera’s
connector panel.
6. Manually rotate the carousel to line up an access hole with one of the
screws.
7. Using the supplied Torx wrench, thread in the first screw but do not
tighten.
8. Manually rotate the carousel to line up with the second screw and use the
Torx wrench to thread in the screw, but do not tighten.
9. Install the remaining two 6-32 x 3/8” Torx flat head screws.
10.Now tighten all four screws. You will need to manually rotate the carousel
as required to access the two captive screws.
Final Assembly
The AFW filter wheel can be used in conjunction with the StarChaser
SC-3-SHORT, which provides self-guiding in front of the filters. It is also
compatible with the SBIG AO-X adaptive optics unit.
1. Reattach the filter wheel cover using the five screws removed in Filter
Installation Step 1.
2. If you are planning to use a StarChaser SC-3 SHORT, it will be installed
directly on top of the filter wheel. Please consult the StarChaser manual for
details.

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3. If you are planning to use an AO-X, it attaches directly on top of the
StarChaser SC-3 SHORT. Please consult the AO-X manual for details.
4. Attach the mounting plate from the camera to the top of the assembly. Be
sure to install the shims, if supplied, in the same locations relative to the
camera. If you are unsure of the correct locations, please refer to the Shim
Sheet included with the camera.
5. Connect the supplied DB-9 cable from the filter wheel’s connector to the
AUX connector on the camera. Be sure to tighten the thumbscrews on both
ends.
Dual Wheel Assembly
If you are planning on using the Dual Wheel option, you will need two identical
filter wheels, plus the AFW-DUAL Dual Filter Wheel Adapter.
The adapter comes with a customized cable, which allows you to connect two
wheels to the AUX port on the camera. One connector on the cable has a
specially designed low-profile back shell, which allows it to fit between the two
wheels with minimal impact on back focus distance.
AFW-DUAL Dual Filter Wheel Adapter
Installing dual wheels requires following the same steps as installing a single
wheel, except for a few additional steps. Please refer to the above instructions
as required.
1. Install the first wheel onto the camera normally.
2. Install the filters normally. Usually, the last slot in the wheel is left empty,
to allow filters in the second wheel to be used with no filter present in the
first wheel.
3. Install the lid normally.

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4. Install the thinner segment of the adapter to the top cover of the first wheel,
using four 6-32 x ¼” socket head cap screws.
5. Now attach the thicker segment of the adapter to the first segment, using
four 6-32 x ¼” socket head cap screws.
6. Remove the cover from the second filter wheel.
7. Locate the filter wheel ADDRESS switch on the edge of the control board.
Address Switch
Up (0) for Filter Wheel 1
Down (1) for Filter Wheel 2
8. Switch the ADDRESS to 1 for the second wheel only. (If only a single wheel
is in use, the ADDRESS must be 0.)
9. Install the dual wheel AUX cable onto the second wheel. The connector
with the custom round back shell must be attached to the second wheel
prior to further assembly. This connector does not require thumbscrews;
the first wheel holds it in place.

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Install AUX cable as shown on second wheel
10.Install the filters in the second wheel.
11.Now attach the second wheel to the adapter. The wheels need to be
installed at right angles, so the motor cover clears.
Dual Wheel Orientation (viewed from camera side)
12.Attach the cover on the second wheel, and finish mounting the nosepiece
adapter and/or StarChaser and AO-X per the standard instructions.
13.Finally, plug the remaining two connectors on the AUX cable into the first
filter wheel and the camera, and tighten the thumbscrews.

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4 –Setting up the Filter Wheel
The following instructions assume you are using the MaxIm LT software, which
is included with all modern SBIG cameras, or MaxIm DL Pro.
If you are using other software the steps will be similar; however, please consult
the user manual for the software being used.
Single Filter Wheel
1. Start MaxIm LT and open the Camera Control Window.
2. Following the instructions in the camera user manual, configure the
software for Camera 1.
3. Now under Camera 1 click Setup Filter.
4. Set Filter or Controlling Camera Model to DL Imaging+FW.
Note: If you are using an SBIG STX or STXL camera, you will have to select a
different option. If you are using SBIG Universal for the camera, you need to
select SBIG Universal for the filter wheel. If you are using SBIG w/AO for the
camera, you will need to select SBIG AO w/FW.
5. Rename the filter slots if required. Double-click on the filter names and
enter a new value.
6. Click OK.
7. Click OK.
8. Click Connect.
Your filter wheel is now ready for use.

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Dual Filter Wheels
If you have installed dual wheels, some additional configuration is required. The
following instructions are for the included MaxIm LT software. You can also
use a current version of MaxIm DL Pro.
DL Imaging –Aluma CCD, Aluma AC, STC Series
Follow these instructions for newer cameras that use the DL Imaging driver.
See below for SBIG Universal based cameras.
The first time after installing the dual wheels the following steps must be
followed:
1. Power up the camera with the dual wheels plugged into the AUX port and
allow it to initialize.
2. Open MaxIm LT. Click the Camera Control icon or press Ctrl-W to
open the Camera Control form and click the Setup tab.
3. Re-select your camera, even if you have done so previously without the
dual wheel installed. This is necessary so the software knows you have a
Dual Wheel. The full procedure is in the camera manual; however, a
brief summary follows:

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Open the MaxIm LT Camera Control window, under Camera 1 click
Setup Camera and set the Camera Model to DL Imaging. Next click
Advanced. In the DL::Config dialog (shown below) click on your camera
model under Devices, then click OK. Click OK again.
4. Next, under Camera 1 click Setup Filter. Set Filter or Controlling
Camera Model to DL Imaging+FW.
5. Click Advanced. The following form appears:

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6. The first filter wheel is “Wheel 1” and the second wheel is “Wheel 2”.
7. Under FW Setup, choose Wheel 1. If you wish, click Defaults to load the
default set of filter names (shown above).
8. To customize the filter slot names, double-click on each Name and enter
a new name for the filter slot. The ID corresponds to the numbers
printed on the carousel.
9. As suggested previously, when loading the filters the last slot in each
wheel should be left empty. It is recommended that the last slot be
labelled “Empty”.
10.Now under FW Setup, click Wheel 2.
11.Again, change the slot names as required for the installed filters. As
before it is recommended that the last slot be “Empty”.
12.Once both Wheel 1 and Wheel 2 have been set up, configure the Slot
Setup.
Slot Setup lets you configure “virtual” filter wheel slots, which map to
specific positions for each of the two wheels.
In addition to the Add Slot, Remove Slot, and Clear buttons, you can
right-click on a slot for a context menu. The Default button will
automatically try to organize the filters using an “Empty” or “Blank” slot
on the opposing wheel.
Example: Primary (wheel 1) has Luminance, Red, Green, Blue, Ha, S-II,
O-III, Empty. Secondary (wheel 2) has U, B, V, R, I, Empty. You can

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configure your “virtual wheel” to show:
Virtual Slot
Wheel 1
Wheel 2
Luminance
Luminance
Empty
Red
Red
Empty
Green
Green
Empty
Blue
Blue
Empty
Ha
Ha
Empty
S-II
S-II
Empty
O-III
O-III
Empty
U
Empty
U
B
Empty
B
V
Empty
V
R
Empty
R
I
Empty
I
13.In this example, when you select the Luminance filter, the primary wheel
will go to Slot 1 for Luminance, and the secondary wheel will go to the
last slot for Empty. If you select I, the first wheel will go to the Empty
slot and the second wheel will go to the I band photometric filter.
14.To save yourself re-entering the slot names in the main configuration
dialog box, turn on the Use slot map names in MaxIm DL checkbox.
You will not need to reenter the slot names in the Setup DL Imaging+FW
dialog box.
15.Click OK to save your changes. Click OK again on the Setup DL
Imaging+FW dialog box.
16.The slot names will automatically appear when you connect to the
camera.
17.Connect to the camera and verify that each slot selects the correct filters.
SBIG Universal –STX, STXL Series
For STX and STXL cameras, you will need to use either the SBIG Universal or
SBIG w/AO driver.
When using the SBIG Universal driver for the main camera, the filter wheel
must be also set to SBIG Universal.
When using the SBIG w/AO driver for the main camera (required when using
the AO-X Adaptive Optics unit), the filter wheel must be set to SBIG AO w/FW.
First, decide on the names of your “virtual slots”, which will map to slots in
wheel 1 and wheel 2. See the table above for an example.
To set up
1. Configure the camera and filter wheel normally, then connect to the
camera. This ensures that the settings file is created. You will be
modifying that file manually.

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2. Disconnect. This step is mandatory before you make any manual
changes to the settings file.
3. If you are using SBIG Universal, open Windows Explorer and navigate to:
Documents\MaxIm DL 6\Settings\CCDPlugSBIG
4. If you are using SBIG w/AO, open Windows Explorer and navigate to:
Documents\MaxIm DL 6\Settings\CCDPlugAO7
5. Double-click the file Settings.txt –this will open it in Notepad.
6. Add the FWSlotMap to the bottom of the file. This is a string containing
a list of virtual slots and the corresponding slots for wheel 1 and wheel 2.
Following the example from the previous section, and using a 10 slot
wheel with the last slot empty, the string will be:
FWSlotMap “Luminance:1:10;Red:2:10;Green:3:10;Blue:4:10;Ha:5:1
0;SII:6:10;OIII:7:10;U:10:1;B:10:2;V:10:3;R:10:4;I:10:5;”
7. Notes:
•The whole text string must be one line (turn off the Word Wrap
feature in Notepad if required).
•The beginning and ending quotes must be included.
•Each filter is defined as Name:Wheel1:Wheel2; –that is the filter
name, the corresponding slot for wheel 1, and the corresponding
slot for wheel 2. The name and wheel slots are separated by
colons (:), and the slot definition is terminated with a semicolon (;).
•The last semicolon before the closing quote is mandatory.
8. Save the file and close Notepad.
9. Connect to the camera in MaxIm LT and verify correct filter wheel
operation. Check each slot to ensure the correct filter is selected.

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5 –Specifications
All AFW series filter wheels have the same external mechanical dimensions.
AFW mechanical layout –dimensions in inches.
Model
Feature
Specification
All AFW Models
Power
Via SBIG Camera AUX Port
Control
Via SBIG Camera AUX Port
Thickness
0.55” (14 mm)
AFW-10-50SQ
Number of Slots
10
Filter Size
50 mm Square
Filter Thickness
1 mm, 2 mm, or 3 mm
Typical Camera
Aluma AC4040, STX
AFW-12-50R
Number of Slots
12
Filter Size
50 mm Round
Filter Thickness
1 mm, 2 mm, or 3 mm
Typical Camera
Aluma AC2020, STXL

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