Moravian 7x50mm or 2″ Filter Wheel For G3 Mark II
The Moravian 7x50mm or 2″ Filter Wheel For G3 Mark II is intended for filters in standard 2″ threaded cells or 50mm glass-only filters. Filter wheel diameter is 190 mm. Compatible with “L” size Mark II adapters.
The ability to capture individual exposures through various filters is one of the key features of the cooled CCD cameras, regardless if being used for scientific research or for astronomical photography. This is why the Gx CCD cameras were designed to include the filter wheel inside the camera head and to integrate filter wheel control into camera control from the beginning. When more than 5 or 6 filters are necessary or the filter wheel has to be used with G4 camera, the filter wheel is too large to be placed inside the camera head. External filter wheel is then the only option.
- Digital electronics PCB is not equipped with internal connectors for filter wheel control, but all necessary signals are routed to single 8-pin RJ-45 connector. This connector is placed between power and USB connectors on the bottom side of the camera shell.
- Camera front shell is 12.5 mm thinner compared to shell for cameras with internal filter wheel. Back focal distance measured from camera front plane is lowered from 29 mm to 16.5 mm.
Controlling of the external filter wheel with electronics already present in the camera head eliminates the necessity to connect the external filter wheel to the host PC (with separate USB or serial cable) as well as to plug in a separate power supply. Only single short 8-wire cable connects the external filter wheel with the camera head.
Another advantage of this design is full compatibility with all software for Gx camera control. External and internal filter wheels are indistinguishable from the software point of view (besides the fact, that external wheel often offers more positions). The SIPS camera control software and also other programs using supplied drivers (The Sky, MaxIm DL, AstroArt or ASCOM compatible programs) control external and internal wheels the same way using the same drivers. When the camera is connected over the Ethernet interface, naturally it is possible to control also the external filter wheel through the TCP/IP protocol.
External filter wheel types
External filter wheels are manufactured in several sizes, depending on the camera series and also on the number and size of filters.
All external filter wheels has the same 17 mm thickness (the distance between the shell back side and the front plate, to which the telescope adapters are mounted). So the distance from the front plate to detector is 33.5 mm.