Screw mount, PENTAX 67, PENTAX 645 lenses and DSLRs
Q: Can S (Screw mount) lenses, PENTAX 67 lenses or PENTAX 645 lenses be used with this camera?
A: These types of lenses can be attached using the respective adapter.(Adapter K 645 for 645/645N/645NII or Adapter B 67 for Pentax 67/67 II) and will operate in Manual exposure mode with stop-down metering. However, shutter release will not be available with default settings. To allow shutter release, change the following settings. (1) Set [Using aperture ring] to [Permitted] in the Custom Setting menu. (2) Set the focus mode lever to MF. Av (Aperture Priority) mode and M (Manual) mode can be used but an exposure error may occur in Av (Aperture Priority) mode. In the viewfinder and status screen, [F--] appears for the aperture indicator. The lens aperture should be set on the lens aperture ring.
Note: The camera operates in Av (Aperture Priority) mode even if the mode dial is set to Auto picture, Picture mode, SCN, Program, SV or TV mode.