SLR camera lens parameters What does it mean
EF-S: EF-S is a digital dedicated head, then the full width of the dark corners. EF can be generic. USM: Ultrasonic motor IS: Image stabilizer Image Stabilizer DO: Multilayer optical diffractive element, currently using DO technology lenses are green circle (green circle is a technical verification mark, the previous fluorite lens Also used green circle) L: luxury, Canon professional lens logo, with red circle said. That is usually referred to as "red circle head" and then is the lens specifications, such as 17-85 / f4-5.6, that is 17mm to 85mm zoom head, wide-angle end of the largest aperture f4, telephoto end maximum aperture f5.6. If the aperture is only a number that is constant aperture, such as 16-35 / f2.8L is 2.8 constant aperture.
1, EF: full-size electronic focus lens (auto focus lens), all Canon digital SLR cameras can be used;
??? EF-S: for the Canon APS-C fuselage lens, can only be used in the APS-C body;
2,18-55mm / 18-135mm: the focal length of the lens, refers to the lens after the main point of focus to the distance, the length of the focal length of the lens determines the size of the image, the angle of view angle; (such as 18-55mm: Focal length from 18mm-55mm zoom lens)
Canon EF is specially configured full frame, but can also be used in APS-C (non-full frame) body
But the focal lengths need to be multiplied by the conversion factor 1.6, is the real lens focal lengths
18-55mm (18-135mm)
Refers to the zoom lens focal length and maximum
