Pentax smc -FA Operating Manual page 6

When using FA lens with the K-mount
Pentax camera having no lens information
contacts, be sure to set the lens aperture
ring to any f-stop other then A. If set to the
"A" position, the lens will automatically be
set to the minimum aperture, causing
improper exposure.
CAUTION :
Be careful not to damage or dirty the lens
information contacts and AF coupler on the
mount surfaces of the camera and lens.
Otherwise, failure or malfunction may
result. If this occurs, wipe them gently with
a clean, dry cloth.
FAJ28-80mm f/3.5-5.6AL and FAJ75-300
mm f/4.5-5.8AL lenses have A (Auto) posi-
tion only, no aperture ring to set a f-stop
manually. The camera body controls aper-
ture settings on "A" position. Camera bod-
ies and accessories that not compatible
with "A" cannot be used.
4
Camera/Lens Mount Compatibility
Pentax camera/lens mount compatibility chart
is shown below.
K -mount
AF2
which is equipped with
Power contacts
AF coupler
Lens information contacts
K -mount
AF
which is equipped with
AF coupler
Lens information contacts
K -mount
A
which is equipped with
Lens information contacts
K-mount
(base mount) -
-will not autofocus, autozoom
or provide automatic electroni-