FUJICA AX-3 Owner's Manual page 19

2. AE LOCK (EXPOSURE MEMORY)
Your Fujica AX-3 has two Shutter Speed Selector settings for automatic
exposure: AE and AEL, and the camera's automatic exposure setting can be
locked when it is set to AE L.
1. When the Shutter Release is pressed halfway down, the shutter speed
(indicated by a red LED) coupled to the preset aperture to accommodate the
brightness of the subject will remain locked until you take your finger
off the Shutter Release. This is referred to as AE Lock (locking the AE or
automatic exposure).
2. The AE lock is useful for making automatic exposure compensation in
back lighted situations. To compensate for back lighted portraits, you
just bring the camera up close to your subject, press the Shutter Release
halfway down and hold it there, then step back and shoot. (Don't take your
finger off the Shutter Release until you trip the shutter).
Note: As long as the Shutter Release is pressed halfway
down, the shutter speed indicating LED will not change
position even if the Aperture Ring is turned. If you want
to use a different aperture, take your finger off the
Shutter Release, reset the Aperture Ring and check the
shutter speed again through the Viewfinder.
3. STOPPED-DOWN AUTOMATIC EXPOSURE
You will have to use stopped down automatic exposure when shooting with a
Praktica screw-mount Fujinon lens (mounted with Mount Adapter X-S), an
ultra-telephoto lens, through an automatic extension bellows, a microscope
(with Microscope Adapter X) or a Macrocinecopy, or with the lens mounted
in reverse (with Reverse Adapter X). And to prevent light from entering
through the finder and fouling up your exposure setting, you will have to
use the accessory eyecup or eyepiece shutter.