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The Starlight Xpress USB Filter Wheel
NEW! Super-Slim Off-Axis guide head add-on
This new filter wheel accessory makes accurate, flexure-free guiding easy to achieve. The extremely slim assembly screws directly to the wheel face and adds only 13mm to the back focal distance of the wheel. The 10 x 8mm prism fully illuminates a Lodestar or EX guider CCD and the pick-off axis may be adjusted to optimise the guide image quality. An alternative filter wheel face plate for direct attachment of our H18 and M26 cameras is also available (not suitable for other SX cameras as the OAG cannot achieve focus for these, without the camera adaptor in place)
A general view of the filter wheel, fitted with T thread adaptors and a 48mm filter disk
The USB filter wheel is a new product for 2009 and introduces many new features to a useful imaging accessory. It is unique in that it does not require a separate power supply when used with USB control - the high performance DC gearmotor runs entirely from the USB supply and consumes less than 100mA. It is also capable of operation from a serial input, or from a switched hand controller, both of which power the wheel from a small dry battery.
The wheel is light and slim, with an easy change system of thumbscrews to swap filter disks without tools. A variety of threaded adaptors is available - T thread, SCT thread and Takahashi 72mm thread at the moment. The adaptors can be swapped by using a small screwdriver to release three stainless screws and lifting off the adaptor flange. Each flange can be rotated to any angle before locking down, so that you can orient the wheel and camera into the optimum position.
The wheel is quiet in operation and the Hall-Effect 3 bit encoded positioning gives absolute filter locations (not serially sequential) so you can easily swap between any filters without accidentally losing the wheel position.
An internal view with the cover removed, showing the 5 x 48mm filter disk with one filter in place. The USB connector is visible at lower left and the Serial/Manual connector is at the lower right.
The 7 x 32.5mm filter disk and the T thread and SCT adaptor flanges
Cross-sectional dimensioned views of the wheel when fitted with T thread and SCT adaptors
Price guide (UK) - approximately £295 for the wheel with one set of adaptors and filter disk.
Now available - CCDSoft plug-in for the SX filter wheel
Here is the latest version of the filter wheel control program. It is now fully compatible with Windows Vista and Windows 7