Ricoh published another product story of the new Pentax K-3 Mark III flagship APS-C DSLR camera and this time they discussed the aperture info record:
“When you mount an older lens and turn the power switch on, the PENTAX K-3 Mark III displays the focal-length selection menu. This is done for two reasons: to save the selected focal length on captured images as EXIF data, and to take advantage of the camera’s advanced SR (Shake Reduction) system. While past models only allowed the choice of preprogrammed focal lengths, the PENTAX K-3 Mark III not only allows you to set the desired focal length, but also to select a previously selected focal length from the history log. In addition, once you select a focal length on the menu screen, the camera carries it over to the next shooting session, eliminating the need to reset the focal length. It even lets you set the desired aperture value using one of the electronic dials, and save it on captured images as EXIF data.
When using some older lenses, such as M-series lenses or A-series lenses with a lens aperture ring, previous models provided automatic exposure setting with closed-down metering, made possible by pressing the Green button in the manual-exposure mode. Designed to automatically perform closed-down metering at the moment of shutter release, the PENTAX K-3 Mark III also provides automatic exposure setting in the Av and TAv modes while the photographer sets the desired aperture using the lens aperture ring. During Live View photography, it also makes real-aperture metering for the aperture set on the lens aperture ring.”
Source: Ricoh