Pentax SLR Operating Manual page 180

178
Lens names and mount names
FA prime lenses (non-zoom lenses) and DA, D FA, FA J and F lenses use
the KAF mount. Of the FA zoom lenses, power zoom enabled lenses use
the KAF2 mount. Lenses without power zoom use the KAF mount. See the
lens manual for details. This camera does not have a power zoom
function.
Lenses and accessories that cannot be used with this camera
When aperture ring is set at other than s (Auto) or a lens without a s
(Auto) position or accessories such as an auto extension tube or auto
bellows are used, camera does not operate unless [Using aperture ring] is
set to [2 (Permitted)] in the [A Custom] menu (p.101). Refer to Notes on
[Using Aperture Ring] (p.179) for restriction that apply when [Using
aperture ring] is set to [2 (Permitted)] in the [A Custom] menu.
All camera exposure modes are available when using DA/FA J or lenses
with Aperture s (Auto) position set to that position.
Lens and Built-in Flash
The built-in flash cannot be regulated and fully fires when pre A lenses or
6
soft lenses are used.
Note that the built-in flash cannot be used as the Auto Flash.