Full-aperture metering and automatic maximum aperture indexing apply when the ring is used with cameras fitted with a meter coupling lever (AI-type cameras). The ring is fitted with a rotating tripod collar at the balance point of the camera/ring/lens combination. The collar is threaded to accept standard 1/4 inch tripod screws, and permits photography with the camera positioned either vertically or horizontally.
Important!
This ring cannot be used with a non-AI type Micro-Nikkor 105mm F/4 lenses.