Introducing Off-Axis Guider Adapter Mark II

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The new line of Moravian Instruments OAGs (Off-Axis Guider Adapters) Mark II is designed to make the guiding camera focusing easier. Despite the guider is typically focused only once upon camera setup, keeping the guiding camera in a stable (non-rotating) position during focusing is convenient. The Mark II OAGs are particularly suitable for the new CG line of auto-guiding cameras, which flat body is designed not to extend the space in front of the OAG.

OAG is a popular mean to use the main imaging telescope to also feed the light to the guiding camera. OAGs are a bit demanding for the telescope optics, as the guider sensor is typically illuminated by the light from the edge of the field of view, diverted to the guider by the OAG mirror. On the other side, star images on the guider camera need not to be perfect and using of OAG brings many advantages compared to usage of standalone guiding telescope.

The guiding camera should be loosened in the original Moravian Instruments OAGs to enable compensation for the guiding port rotation during focusing. The new Mark II OAGs keep the guiding camera port stable on two precision rails. Focusing is done by a knurled wheel. Also, the focused position is not locked using the knurled nut on the guiding camera port thread, but by tightening the screws on the tails.