Bought a Canon camera lens on the EF 24-70mm f / 2.8L USM what it means
L: Luxury luxury, Canon high-end professional lens logo, but also many photographers for it at the expense of the lens, its logo for the front of the lens red mark.
USM: Ultra Sonic MOTOr ultrasonic motor, which is split ring ultrasonic motor (Ring-USM) and micro-ultrasonic motor (Micro-USM) two. At present, USM ultrasonic motor in the Canon lens has been widely used, even the most low-end amateur lens.
24-70: zoom lens, the minimum wide-angle end focal length 24mm, the maximum focal length of the focal length of 70mm
F / 2.8: constant aperture of 2.8, the aperture does not change with the increase in focal length
EF 24-70mm f / 2.8L USM
EF: Electronic Focus electronic focus, Canon EOS camera bayonet name, Canon is the original lens series name.
Canon EF-S 55-250mm f / 4-5.6 IS lens better. This with anti-shake function. Equivalent to the shutter speed increased 2-4 files.
