The Pentax 75mm/2.8 Leaf Shutter Lens: With camera set to Leaf Shutter Mode focal plane shutter is set to 1/8 enabling use of Programmed Auto and Manual Flash operation through X-sync terminal.
Otherwise, this lens can be used as normal (leaf shutter not used, focal plane shutter in camera is) in Lens-set Aperture Priority Mode or Manual Mode.
Diaphragm: Fully automatic (non-Program) Flash Sync Shutter Speeds: 1/60 to 1/500