TS Optics 2" Off Axis Guider for refractors, SCs, RC telescopes with only 27 mm length
For capturing and guiding with the same scope - with excepional characteristics.
The off axis guider is an important accessory for the astro photography. At integrating times longer than ca. one minute, the tracking has to be controlled. For this task, one can use a guiding scope or an off axis guider.
Advantages of an Off Axis Guider
An additional guiding scope raises the mount´s load and decreases stability. A guiding scope with adjustable clampshells is often more expensive than an off axis guider.
But the main feature, anyway, is the fact that one and the same optical system is used for capturing and guiding. No mechanical part can bend or shift and cause elongated stars. You always have optimal resolution for guiding because of the same focal length.How does an Off Axis Guider work?
This is really simple - on the rim of the guider is a little prism that lies for the main sensor outside the field of view. All stars seen by that prism can be used for guiding. Observation is done by a sideward connector for a crosshair eyepiece or a guiding camera.Suggested use for an Off Axis Guider
The off axis guider is made for long-term astrophotography (1-2 minutes or more). With longer integration times, stars may be elongated what makes a tracking control necessary.Advantages of the TS OAG 27
According to our experience, the Celestron Radial Guider is one of the best off axis guiders available on the current market. But it has relatively long optical path and, due to the SC connector, only useable for SC telescopes. So we reworked this guider completely without loosing its advantages and turned it to the TS OAG 27.
You can twist the guiding prism by ca. 100° without loosening the guider. Camera-mounting-scope remain one unit. Only if no guiding star can be found in this area, the guider has to be loosened - a unique system! With other guider, you always have to loosen everything - you may imagine what happens to your precise focus in this case.
To scan a larger guide star area, the prism can be tilted by a micrometre screw - precisely and very elegant! The prism is spring loaded to prevent any play.
Even heavy cameras, filter wheels etc. are carried with good stability because everything has a stiff connection to the telescope.
The result: You have no problems with finding a guide star and operating the guider is even possible when wearing gloves.Adaption to the telescope
The TSOAG27 has a short (6 mm) 2" barrel with a female M48 (2") filter thread at the telescope side. This allows particularly easy adaptions to the telescope:
Connection of the camera(s) or crosshair eyepiece
Connection to 2" focusers: extend the 2" barrel with a 2" extension tube and use the off axis guider with 2" focusers
connection to the 2" SC thread: an adapter to the SC thread. Ideal for all Schmidt-Cassegrain telescopes, many Maksutovs and the f/6.3 reducers.
connection to the M48 thread: no adapter needed, this thread is already available
connection to the T2-thread: an adapter reduces the M48 thread to T2 and allows for connectiong to lenses and telescopes with male T2-thread.
The TSOAG27 has a T2 thread at both connectors. Starting from the T2-thread there are many adaptions like
reduction to 1.25" for crosshair eypieces
T2 rings for all common SLR cameras
reduction from T2 to C-mount
different T2 extension tubes for fine tuning
Distance prism middle to the lateral T2 connector: 37 mm
Distance prism middle to the camera side of the TSOAG27 without T2-thread: 15 mm
Distance prism middle to the front of the TSOAG27: 18 mm
Length of the 2" receptacle at the telescope side: 7 mm
Length of T2-thread: 5 mm
Length of M48 thread at the telescope side: 5 mm
Length of T2-thead at the dome: 7 mm
For capturing and guiding with the same scope - with only 27 mm length