A Pentax screw mount to K mount adapter is available (see my Pentax accessory page) which allows screw mount lenses to be used on K mount digital or film cameras. For using screw mount lenses on the Pentax digital camera you go into the "custom" camera menu. One of the last items in the custom menu is 'allow manual lenses'. Buy and adapter, adjust the camera to accept manual optic and you are set to go.