Pentax -D - Manual (Page 16)

APERTURE CONTROL 14
Setting the aperture to “A”(Auto)
Turn the aperture ring to align the aperture-A index with the white line while depressing the
Aperture-A-lock button. The aperture ring can be released from “A” in the same manner
to set your desired f-stop manually.
• If the camera has the K
AF2
lens mount and the aperture is not set to A, the approximate
aperture setting will be displayed on the display panel and in the viewfinder.
• If the camera has the K lens mount which has no electronic contacts to transmit the lens
information, set the aperture to any f-stop other than A.