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TS Optics TSOAG9T2 Off Axis Guider

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TS Optics Off Axis Guider - ultra-low profile - only 9mm optical length

The new TS Off Axis Guider is the lowest profile off axis guider that we know off. Despite this, no compromise has been made with the function and operating comfort of this versatile Off Axis Guider.


Advantages of Off-Axis Guiding

No mechanical flexure between main and guiding telescope

The load for the mount is much reduced

There is no need for a guide scope and the setup will remain more compact.

You work with the main telescope's resolution and focal length Not with the typically lower resolution of a guide scope


Advantages of the TS OAG 9

The ultra-low profile design and the various available adaptations offer many unique advantages:

It can be used with correctors and DSLR's. This is the only Off Axis Guider that can be used between a coma corrector (or field flattener) and a DSLR camera without upsetting the tolerance for the distance between camera and corrector.

It can be used with cooled CCD cameras: The off axis guider provides enough space for filter wheels or filter drawers when using cooled CCD cameras.


In Use

Place the TS Optics Off Axis Guider behind the corrector. The TS Optics Off Axis Guider is used between the corrector and the camera. Using an off axis guider in front of the corrector is not useful. The guide star would be distorted, the distances on both optical paths are too different and you might even get focusing problems with the main camera. Behind the corrector you can avoid these problems, but this only works due to he low profile of the Off Axis Guider

Compared with many simpler guiders, the TS Optics Off Axis Guider not only has a shorter overall length, but also a larger clear aperture. A "T2 keyhole" can be avoided, resulting in better illumination for large sensor cameras up to 45mm diagonal (FX format / traditional 35mm film).

T2 Thread. This provides the widest choice of adaption. With it you can attach most filter wheels, filter drawers and CCD cameras like those from ATiK or Artemis. Of course you can also attach SLR cameras using a standard T2 bayonet ring.

We offer various T2 extension tubes between 7.5mm and 40mm length. That way you can adjust the spacing of both the main camera and the guiding camera.


Specifications and Functionality

The TS Optics Off Axis Guider can be used with almost any telescope-adaptor-camera combination. We offer a variety of adaptations for almost all conceivable applications. If in doubt, please ask for help.



Telescope Adaptation. 2" barrel base with M48 filter thread inside (fits the M48 barrel extension)

Camera Adaptation. Standard T2 thread for the adaptation of filter wheels or other adaptors

Side Turret Adaptation. T2 thread for Autoguiding cameras. 1.25" eyepiece adaptation possible

All screws and threads are metric (M4)

Length: The optical length of the off axis guider is only 9mm in the direction towards the main camera. (Not counting the length of the 2" barrel base)

Focusing mechanism for the guiding eyepiece or autoguider: Each Off Axis Guider needs to have a provision for focusing the guiding star individually. First you focus the main camera with the telescope's focuser. After that the guiding turret must offer its own focusing mechanism that allows you to focus the guiding camera (or eyepiece) without changing the focus for the main camera. The TS Optics Off Axis Guider offers a simple solution.

The T2 disc on the guiding turret is the part to which the eyepiece or autoguider is connected. This disc can be moved along the turret, thus changing focus. The disc is fixed in position with either a slug screw or a thumbscrew. No spacer rings or other inconvenient means for focusing are needed.


Guide Star Search. This is made easy by the prism moving mechanism: This is every bit as important as focusing: Finding a suitable guiding star. Simple off axis guiders only offer a "one-dimensional" ring around the target object for finding a guiding star. This is often done by rotating the off axis guider as a whole. The radial distance between the guide star and the object cannot be influenced directly. Often this limited area is not enough for finding a suitably bright guiding star, especially in telescopes with less than 10" aperture. The TS Optics Off Axis Guider allows you to move the prism radially. This increases the "one dimensional" ring to a "two-dimensional" disc, ultimately multiplying the number of available guide stars. On a typical large sensor DSLR camera (FX size) you can move the prism by up to 8mm - on smaller sensor cameras an even larger interval may be available.

Even with a 24x17mm sensor (DX / APS-C sensor e.g. in most DSLR cameras) you have at least 4mm range of movement even in the worst case position of the sensor, i.e. when the long axis diagonal of 29.4mm is pointed directly towards the prism. In all other orientations of the camera's sensor the movement range is larger. This 4mm+ range and the possibility to rotate the off axis guider provides a large enough area for finding a guiding star in all cases! The turret that moves the prism is locked with a thumbscrew. The dovetailed profile of the turret provides a strong grip even without the need for using a wrench. When you move the turret it does not change the focus of the guiding camera.




Product Note Status Price
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£12.50 *
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£25.50 *
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