| PK-R or K-PR or or any other version of the K mount refers to a Pentax/Ricoh derivative of the Pentax K mount. It a it has an extra pin at about the 4:30 position looking at the lens mount, right where the Pentax AF drive is. That pin sometimes gets stuck in the AF drive. The pin does nothing with the Pentax DSLR bodies, so it is safe and advisable to disable it before mounting it on your body. |