Product Highlights: Aperture has range of f/2.8-22 Aspherical Lens Element STM Stepping Motor for Even, Silent AF EF Mount Lens Light in weight and Small: 4.6 oz, 1″ Long Lens Coverings Reduce Flare and Ghost Seven-Blade spherical Diaphragm Minimum Focus Distance of 11.81inches 64mm Equivalent on APS-C Cameras STM Focus in Video on pick EOS Rebels This EF 40mm f/2.8 STM Lens from Canon is an addition to Canon’s line-up of EF lenses–a light, unremarkable “normal” lens. At a very lightweight 4.6 oz, this is one of the lightest lenses in the EF family. It’s less than 1” long, so it will never draw unwanted awareness to you when you’re shooting in open. A clear f/2.8 maximum aperture enables you to shoot in pretty much any lighting circumstances, and the complicated lens configuration, including 1 aspherical element, guarantees top image quality from the center to the end of the frame. The optimized coverings used in building the lens greatly decrease ghosting and flaring, and deliver excellent color balance. STM functionality gives calm, smooth and constant autofocus during video operation (constant video autofocus only when used with Canon EOS 70D, Rebel T4i and T5i). The spherical aperture formed by seven diaphragm blades joint with the wide aperture can provide you beautiful bokeh–the out-of-focus background areas of images. This 40mm lens will give you a view equivalent to 64mm while used on a camera with an APS-C sensor, and is capable to focus as close as 11.81inches. Lately developed STM technology for even and quiet permanent AF while shooting video (continuous video autofocus only supported with EOS 70D, Rebel T4i & T5i cameras). Light in weight and unremarkable 4.6 oz lens is less than 1” long. Bright f/2.8 aperture is helpful in low light circumstances and gives shallow depth of field focus control. Top image quality from the center to the edge thanks to its superior lens configuration including 1 aspherical element. Optimized coatings that minimize ghosting and flare while providing exceptional color balance a circular seven-blade aperture for stunning soft-focus backgrounds Short minimum focusing distance of just 11.81inches Mounted over a camera with an APS-C sensor, this lens varies a view like to a 64mm lens in 35mm format.