The pentax SDM FA 645 55mm f/2.8 is the first model of the pentax-D FA 645
lens series created for the pentax 645D digital medium-format camera. With a
focal length that's equivalent to a 43.5mm standard lens (in 35mm), it features
optics optimised for digital photography to assure exceptional performance, and
also affords an image circle covering the image area of existing 645-format
film SLR cameras. It has dependable, dust-proof, weather-resistant construction
for active outdoor photography.