FUJICA AX-3 Owner's Manual page 35

1. Auto-diaphragm lug
(Stops down the aperture to the preset value just before exposure by the
operation of the Aperture Control Lever in the camera body.)
2. Full aperture signal pin
(Having a special built-in resistor for full aperture, it signals the
viewfinder indicator and auto strobe circuits in the camera body on
contact with a pin in the body.)
3. Aperture keying lug
(It signals the f-number to the camera body, works at 6 degrees intervals
per step, and stops the aperture down to minimum when the Aperture Ring is
set for the orange mark.)
4. Lens auto/manual groove
(When a DM lens is mounted, it presses in the auto/manual pin in the
camera body to activate the automatic aperture setting circuit, and when
the lens is on manual, it activates the circuit for stopping the aperture
down to the preset value.)
X-Fujinon Lenses (Lenses without the Mark on the Aperture Ring)
These can be used for full aperture metering and aperture-preferred
automatic exposure but not for programmed and shutter-preferred automatic
exposure. They are not provided with functions (2) and (4) of the DM
lenses.
3. USING PRAKTICA SCREW-MOUNT FUJINON LENSES
These lenses are mounted on your Fujica AX-3 with the Mount Adapter X-S
(optional). The procedure for taking pictures is explained below. For
details read the instructions packed with the adapter.