FUJICA AX-3 Owner's Manual page 21

Note:
If you are shooting with the Shutter
Speed Selector set to AEL, be sure
to press in the Preview Button
before you press the Shutter Release
halfway down because your picture
will not turn out properly exposed
if you do it the other way around.
Shooting with an Ultra-telephoto Lens, with the Lens Mounted in Reverse,
and through an Auto Extension Bellows.
1. Set the Shutter Speed Selector to AE or AEL.
2. Set the Aperture Ring to the desired value.
3. Look through the Viewfinder and press the Shutter Release halfway down
to make sure that neither the overexposure nor the underexposure warning
signal is blinking.
4. Take your picture by pressing the Shutter Release gently down.