This lens is an EF 28mm 1.8 USM

Features
Focal length and maximum aperture: 28 mm 1:1.8
Lens construction: 10 elements in 9 groups
Diagonal angle of view: 75°
Focus adjustment: Rear focusing system with USM
Closest focusing distance: 0.25m / 0.8ft
Filter size: 58mm
With the large maximum aperture, excellent background blur is possible
even with a fast shutter speed
The large maximum aperture makes excellent background blur possible even
with a fast shutter speed.
The aspherical lens element makes the lens compact and corrects
spherical aberrations.
The image is sharp even at the edges.
Photo Quote: There are an awful lot of people in the world and it's going to be terribly hard to photograph all of them... It was my teacher Lisette Model who finally made it clear to me that the more specific you are, the more general it will be. Diane Arbus