Terminology related to SLR camera lens.

There are many terms in this respect. Let me give an example of Canon: AFD: Arc-driven arc motor. Early EF lenses were equipped with AFD motors, which were not as fast as USM motors and had a louder focusing sound. Aluminum: aspherical lens. Do: multilayer diffractive optical element multilayer diffractive optical lens, which was first applied to the lens by Canon in 2000. It has the characteristics of fluorite and aspheric lens, and can effectively suppress dispersion and correct spherical aberration. At present, it is mainly used in the field of telephoto lenses. * * * There are three lenses: EF 400mm F4 DO is USM, EF70-300mm F4.5-5.6 DO is USM, and E800mm F5.6DO is USM. EF: Electronic Focus, the bayonet name of Canon EOS camera, and also the serial name of Canon original lens. Ef-s: electronic bayonet of APS-c digital SLR camera. This is an electronic lens specially designed by Canon for its APS-C digital SLR camera. It can only be applied to Canon DSLR in APS-C format, and its notable feature is that there is a white square at the interface for aligning the camera body. Emd: electromagnetic aperture of electromagnetic diaphragm. The electromagnetic drive aperture control elements of all EF lenses are integrated components of deformable stepping motors and aperture blades, which are controlled by digital signals and have high sensitivity and precision. FL: fluorite fluorite, a kind of calcium fluoride crystal, has extremely low dispersion, and its ability to control chromatic aberration is better than UD ultra-low dispersion lens. Fp: focus preset FP: focus preset ftm: full-time manual focusing. That is: image stabilizer, that is, lens anti-shake system. Canon's first anti-shake lens is Ef75-300mm4-5.6isusm released by 1995, which is also the first anti-shake lens in the world. L: Luxury is the symbol of Canon's high-end professional lens, and it is also a lens for which many photographers are willing to go bankrupt. Its logo is the red mark in front of the camera. MM: Micro-motor Micro-motor is a traditional motor with transmission shaft, which consumes a lot of power and does not support full-time manual focusing. It is mostly used for cheap low-grade lenses. Sf: soft focus SF: soft focus. S-ud: ultra-low dispersion lens, high performance ultra-low dispersion, optical performance close to fluorite lens. Tilt shift lens shift lens. Axis shifting lens is mainly used in the fields of architecture, landscape and commercial photography. At present, Canon has three TS lenses * * *: TS-E24mm F3.5L, TS-E45mm F2.8, TS-E90MMF2.8..UD UD: ultra-low dispersion ultra-low dispersion lens. The effect of using two UDs together is usually similar to that of using fluorite lenses. USM: Ultrasonic motor Ultrasonic motor is divided into ring ultrasonic motor and miniature USM ultrasonic motor. At present, USM ultrasonic motor has been widely used in Canon lens, even the lowest amateur lens. Example: EF70-200mm F4L is USM lens, which means L-class professional lens with Canon EF mount, focal length of 70-200mm, and maximum aperture constant F4. It is an anti-shake system and USM ultrasonic motor, commonly known as "I love Guo Xuwei". Whether it helps you.