SMC Pentax FA 50mm f/1.4
The Pentax SMCP-FA 50mm f1.4 lens has a fully automatic diaphragm. At 1.5 inches long and weighing just 7.8 ounces, you can take this 50mm fixed focal length lens with you everywhere. You can use this lens with all Pentax SLR cameras, but the AF system only works with Pentax AF cameras.