The optical design consisting of six groups of 6 groups, including two non -sphere lenses, achieves both high image quality and compactness.The optical design with the inner focus system is at 0.08 seconds at the fastest AF, combined with a stepping motor.The exterior is equipped with metal parts on the entire surface, and is equipped with a low-temperature structure of dustproof, drip-proof, and -10 ° C.- lens configuration 9 groups (1 edo spherical lens) Focal Distance f = 50mm (35mm format → 76mm equivalent) angle of view 31.7 ° Maximum caliber ratio (open aperture) F2 minimum aperture F16 aperture format 9 pieces (circular aperture), 1/3 step (19 steps in total) shooting distance range 39cm - ∞ Maximum shooting magnification 0.15 times External dimensions Maximum diameter x length (approx.)? 60mm x 59.4mm * From the tip to the mount reference surface mass (approx.) 200g * Not included lens cap/food Filter size ? 46mm bundled product Lens cap-46, lens rear cap RLCP-001, lens hood, wrapping cross