The K35's were developed in the 1970s...
in response to the growing popularity of the Zeiss Super Speeds and also won an Academy Award in 1976 for technical achievment. Drawing similarities but excelling in many areas over the Zeiss counterparts, one of the standout features of the K35's is the ability to cover full frame sensors.
and 12 iris blades for natural looking bokeh
Full Frame Coverage
for future large format cameras