Focal Length: 180 mm Focal Length effective: 180.13 mm Equivalent 35 mm @ 33x44 mm : 141 mm Equivalent 35 mm @ 40x54 mm : 116 mm Image circle: 120 mm Shift @ 33x44 mm: horiz. 36 mm / vert. 39 mm Shift @ 40x54 mm: horiz. 30 mm / vert. 34 mm Close focus distance: 2.20 m Filter thread: 55.0 mm Best f stop digital: f 8 - f 11 Best f stop film: f 8 - f 16 Shutter: Copal 0, 1sec - 1/500sec, B, T Product remarks: Schneider Apo-Digitar 5.6/180 mm T, SB34, adjusted by Schneider-Kreuznach to ALPA standard