MOAG means Manual Off-Axis Guider. It allows you to guide your telescope to obtain sharp, round stars by guiding in front of your filters using unfiltered light in the same optical beam as your imaging camera. This is particularly important for practical use of narrowband filters. It also eliminates potential differential flexure if you guide with a separate guide scope. With modern, automated data acquisition programs, framing your imaging target and placing a guide star in the guide camera is simple and no longer an issue, particularly if you have a remotely-controlled camera rotator.
The MonsterMOAG™ (MMOAG) is specifically designed to accommodate the larger CCD imaging detectors (36 x 36 mm), such as the Kodak KAF16803E and KAF9000E. Furthermore, at 1.25" thick, it has one of the thinnest backfocus for an OAG available, making MonsterMOAG™ an ideal choice for systems with minimal backfocus, such as the Takahashi FSQ106N refractor. However, it is strong enough to handle heavy loads from larger cameras and filter wheels.
When installed, the MonsterMOAG becomes a fixed part of your optical train along with your camera and filter wheel. When you rotate your camera at the back of your telescope, these three components will rotate together. This means that the guide camera location will be fixed relative to the imaging camera. You define this once as your Field-Of-View-Indicator (FOVI) in programs like Software Bisque's TheSkyX. Then you can frame your target while ensuring that the guide camera has a star to guide on.
The MMOAG introduces the capability of attaching up to 4 guide ports to the MonsterMOAG. This was accomplished by making the body square and adding a hole on each side for insertion of the pick-off prism from the guide port assembly. Thus, one possibility could include one guide camera and one 1.25" eyepiece, for example. You can purchase the MMOAG with 1, 2, 3, or 4 ports. Any unused guide port will be shipped with a removable black metal plate. Extra guide port assemblies can be ordered at a later date. The thickness (backfocus) and adapters are the same as before.
