Focal length and maximum aperture 300 mm 14 lens construction 15 elements in 11 groups diagonal angle of view 8 degrees15 rear focusing system with usm closest focusing distance 15m 49ft filter size 77mm compact l series telephoto lens with an image stabilizer which compensates for camera shake with equivalent effect of a shutter speed two stops faster two image stabilizer modes are provided stabilizer mode 1 the same mode featured on the ef 75 300mm f4 56 is usm and the new stabilizer mode 2