Product Includes Aperture Range: f/1.8 to 22 Inner, back Focusing System Distance Scale Minimum Focus Distance is 2.8′ EF Mount Lens 58mm Filter Thread Diameter Ultrasonic Focus Motor The EF 85mm f/1.8 USM Lens from Canon is extremely practical medium telephoto main lens best for a range of applications including portraiture. Its express f/1.8 maximum aperture is efficient in low light and perfect for shallow depth of field focus control. An ultrasonic autofocus motor (USM) gives quick, soft and silent AF action and for the reason that the front lens group doesn’t revolve throughout polarizing, focusing and special filter effects can be used efficiently. Fast Maximum Aperture A dazzling f/1.8 maximum aperture makes this lens a fine choice for low-light photography and offers low depth of field ideal, control for portraiture with satisfying background blur. Ultrasonic Autofocus Motor With this ultrasonic motor (USM), the autofocus action on this lens is quick, even and nearly silent.