EF: indicates that the lens supports full-frame; APS-C format lenses are denoted by EF-S; shift lenses are identified as TS-E;
70-200mm: the focal length of the lens. The larger the value, the larger the distant subject can be photographed (telephoto), and the smaller the value, the wider the range that can be photographed (wide-angle);
F2.8: maximum aperture. Used to indicate the amount of light through the lens, the smaller the value, the greater the amount of light through the lens, the higher the shutter speed, the greater the degree of bokeh in front of and behind the subject;
L: is the abbreviation for Luxury (luxury), indicating that it is a high-performance lens of Canon, the red circle in front of the lens, that is, the logo of the L lens. In addition, when the logo is DO, it means that the lens is equipped with a miniaturized lens with multi-layer diffractive optics, and the green circle in front of the lens is the logo;
IS: It is the abbreviation of IMAGE STABILIZER, which means that the lens is equipped with a hand-shake compensation mechanism, that is, anti-shake;
II: Type II or Type III, in the past, there have been lenses with exactly the same focal length and aperture, in order to distinguish the lens from the lens.
Type II: Type II or Type III, in the past there have been lenses with exactly the same focal length and aperture, in order to distinguish between the old and new products will use Roman numerals;
USM: short for ULTRA SONIC MOTOR, which means that the lens focus is driven by an ultrasonic motor, and lenses that use a DC motor don't have this mark.
Extended Answer:
Canon's product line*** is distributed in three major areas: personal products, office equipment and industrial equipment, and its main products include cameras and lenses, digital cameras, printers, copiers, facsimile machines, scanners, broadcasting equipment, medical equipment and semiconductor production equipment. Headquartered in Tokyo, Japan, and with four regional sales headquarters in the Americas, Europe, Asia and Japan, Canon has 200 subsidiaries around the world and employs more than 100,000 people.
Canon (Canon ), is a Japan's world's leading integrated group of production of imaging and information products, since its establishment in 1937, after years of unremitting efforts, Canon has globalized its business and expanded into various fields. The founder of Canon was a Japanese medical doctor, and the name was inspired by his looking up at the sky. The original name of Canon was "Seiki-kougaku-kenkyuujo" (Seiki-kougaku-kenkyuujo or Precision Optical Instruments Laboratory), which was a precision optical instruments laboratory.