TS Optics Off Axis Guider - ultra-low profile - only 9mm length directly for Canon EOS
The short TSOAG9 off-axis guider is a development from Teleskop Service. It can be used with almost every telescope and substitutes the guiding scope. The TSOAG9EOS is optimized for Canon EOS DSLR cameras and allows the adaption if only little space is available.Advantages of Off Axis Guiding
Advantages of the Off Axis Guider
No mechanical flexure between main and guiding telescope can possibly ruin the tracking accuracy if you use an off axis guider.
- 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 telescopes resolution and focal length, not with the typically lower resolution of a guide scope.
The ultra low profile design and the various available adaptions offer many unique advantages
Can be used with correctors and DSLR
The only Off Axis Guider that can be used between a coma corrector (or field flattner) and a DSLR camera without leaving the tolerance for the distance between camera and corrector.
Can be used with cooled CCD camera
The Off Axis Guider provides enough space for filter wheels or filter drawers when using cooled CCD cameras.Place the OAG behind the corrector
The TS OAG 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 the low profile of the OAG!Large clear aperture
Compared with many simpler guiders the TS OAG not only has a shorter overall length, but also a larger clear aperture. A "T" keyhole" can be avoided, resulting in better illumination for larger sensor cameras up to 45 mm diagonal.Directly connection to Canon EOS
The special low profile connection ring for Canon EOS is directly enclosed.Technical details
- Telescope adaption: 2" barrel base with M48 filter thread inside
- Camera adaptation: Canon EOS bayonet
- Side turret adaption: T2 thread for autoguiding cameras or 1 1/4" eyepiece adaption possible
- All screws and threads are metric (M4)
Distance from the middle of the prism to the lateral T2 connection: 26 mm to 38 mm adjustable
- Distance from the middle of the prism to the front side of the TSOAG9: 6.7 mm
- Distance from the middle of the prism to the camera side of the TSOAG9: 4.5 mm
The optical length of the Off Axis Guider is only 9 mm 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 good quality Off Axis Guider needs to have provision for focusing the guiding star individually. First you focus the main camera with the telescopes focuser. After that the guiding turret must offer its own focusing mechanism that allows you to focus the guiding camera (or eyepiece) without changing focus with the main camera! The TS Off Axis Guider offers a comfortable focusing mechanism:
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 space rings or other inconvenient means for focusing are needed.
Guide star search - made easy by the prism moving mechanism:
This is erery bit as important as focusing: Finding a suitable guiding star. Simple Off Axis guiders only offer a "one-dimensional" ring around the target object object for finding a guiding star. This 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 OAG9 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 you can move the prism by up to 8 mm - on smaller sensor cameras an even larger interval may be available.
Even with a 24 x 17 mm sensor (e.g. in most DSLR cameras) you have at least 4 mm range of movement even in the worst case position of the sensor, i.e. when the long axis diagonal of 29.4 mm is pointed directly towards the prism. In all other orientations of the cameras sensor the movement range is larger. This 4 mm + range and the possibility to rotate the Off Axis Guider provides a large enough area for finding a guiding star in all cases!
Possible telescope adaptions
The TS OAG´s M48 thread allows for a broad variety of adaptations without being forced to use the "T2 keyhole", i.e. the small clear aperture available when a T2 adaptation must be used. This "keyhole" might result in vignetting.
- TS OAG9 Off Axis Guider
- Canon EOS adaptation (TSO-TSOAG9-EOS)
Extremely low profile Off Axis Guider (9mm) with connection for Canon EOS.