A comprehensive introduction to the data on the lens of SLR camera

SLR lens data are very common: aperture: marked as 1: x or 1: x-y on the lens, the former is constant aperture, The latter is that there is a maximum aperture at the minimum focal length and a minimum aperture at the maximum focal length ~ ~ Under the same parameters, the larger the aperture means the better the quality of the lens ~ ~ Focal length: there is a difference between fixed focus and zoom ~ ~ As the saying goes, the quality of fixed focus is better than that of zoom lens ~ ~ ~ But zoom lens covers a wide range and is easy to carry, so it is often said that a lens with a small minimum focal length means a wide-angle end ~ ~. The greater the maximum focal length, the greater the magnification ~ ~ ~ However, the barrel distortion and pillow distortion should be paid attention to in large zoom lenses ~ ~ The selection of lens aperture: filter, UV, polarizer and hood. Lens mount: EOS C, Nikkor N, PK P, M of SONY and R of Leica, and other secondary lens parameters include lens composition and number (X groups of X films), coating condition (low dispersion, etc.), whether there is lens anti-shake, which frame machine is suitable for (APS and full frame, etc.), whether it is manual zoom, manual aperture, manual focusing or automatic lens. Auto lens motors include ultrasonic motors, ultra-quiet motors and the like ~ ~ Because the sensor doesn't understand that the actual focal length represented by the focal length of the lens is different, there is generally a conversion factor to change to the standard focal length ~ ~ ~ ~ Finally, there are some professional indicators when evaluating the lens. Baidu or google will do it ~ ~ I hope to help you.