OAG Off Axis Guider Adapter for Moravian Instruments G4 Mark II Cameras
Please order this version of the OAG only for a MARK II version of a Moravian Instruments G4 camera.
Off-axis Guider (OAG) adapters are designed to allow attachment of any guiding camera with 1.25" eyepiece nosepiece, although the nosepiece must be somewhat short to achieve focus.
Off-axis guider adapters for G3 and G4 cameras are equipped with M68 × 1 thread on the telescope side at the distance of 61.5 mm from the detector. The two variants (for G3 cameras and for G4 cameras) differ in the mounting holes' placement and also in the distance of the reflecting mirror from the optical axis.
Connection of the guide camera is via a 1.25" nosepiece. It also comes with an adapter with a male C-mount thread to connect to cameras with that type of thread or we also supply a C-mount to T-thread adapter, then a camera with female T-thread can be connected, too.
Note the G3-OAG is manufactured for “L” size adapter base, so it is compatible with “M” and “L” external filter wheels only.
While G2-OAG (with M48 × 0.75 or M42 × 0.75 inner thread) for “S” size adapter base can be technically mounted to “S” size external filter wheel, the mirror is so close to optical axis, that it partially shields sensors used in G3 cameras and G2-OAG cannot be used.
When used on camera with Internal filter wheel, thin adapter base is used.
If the OAG is used on camera without filter wheel, thicker adapter base must be used to keep the Back focal distance and to allow the guiding camera to reach focus.
OAG guider port is compatible with G0 and G1 cameras. It is necessary to replace the CS/1.25” adapter with short, 10 mm variant in the case of G1 cameras. Because G1 cameras follow CS-mount standard, (BFD 12.5 mm), any camera following this standard with 10 mm long 1.25” adapter should work properly with the G3-OAG.