The Pentax 120mm f4 SMC FA Macro is a short telephoto macro lens with manual and autofocus operation for use with Pentax's 645 medium format digital SLRs.
The lens features a 1:1 magnification ratio, a close focusing distance of 39cm, extra-low dispersion (ED) glass to correct for chromatic aberrations and Super Multi Coating (SMC) which significantly increases light transmission.