FL-YFL3528 / FL-YKL3528 Product specifications Format size Focal length Maximum aperture ratio Iris range Mount Field of view Minimum object distance Back focal length Filter size 45 mm Image circle 35 mm 1:2.8 2.8∼22 F-mount (bayonet mount) FL-YFL3528 K-mount (PENTAX bayonet mount) FL-YKL3528 57mm (Magnification: 0.5x) 70mm (Magnification: 0.5x) 81mm (Magnification: 0.5x) 0.19m (Magnification: 0.5x) 33.22 mm 62 P=0.75 mm Dimensions Min.~Max. Magnification Weight Remarks 380 g Focus: Lock Screw Iris: Click stop. Not for photographic cameras.