Specifications

Every filter position in the wheel is defined by the index hole. The hole
defining the first position is preceded by another hole.
Older versions of G2 cameras (revisions 1 and 2) have a filter wheel of 98 mm
diameter, later versions (revisions 2 and 3) use filter wheels of 95.5 mm
diameter. Filter numbering is illustrated by the following pictures:
56
Illustration 28: Filters can be changed after opening the camera case front shell