85mm F1.8 Telephoto Manual Focus  EF Lens Camera Lens for NIKON CAMERA

85mm F1.8 Telephoto Manual Focus   Ef Lens Camera Lens for NIKON CAMERA

EF Lens is a lens mount standard designed and produced by Canon for its EOS series of digital single-lens reflex cameras (DSLR).

"EF" is the abbreviation of "Electro-Focus". As the name suggests, it emphasizes that the communication and control between this lens and the camera body are completely

carried out through electronic signals, without traditional mechanical linkage. Canon launched the EF mount in 1987, which marked the birth of the Canon EOS system and

EF lens series, and opened the era of full electronicization of camera systems.

Main features of EF lens:

Fully electronic mount: There is no mechanical linkage between EF lens and Canon EOS SLR camera. All focus, aperture control, anti-shake and other functions are exchange

d and commanded through electronic contacts. This makes the control of the lens by the camera body more accurate and efficient.

Large mount diameter: The EF mount has a mating diameter of about 54 mm (outer diameter of about 65 mm) and a flange focal length (the distance from the mount base

plane to the focal plane) of about 44 mm. This large aperture design gives Canon optical engineers greater freedom to design lenses with larger apertures and higher

performance, such as the early f/1.0 lenses.

Compatibility: EF lenses are primarily designed for Canon's full-frame and APS-C EOS SLR cameras.

EF lenses: They can be used with all Canon EOS SLR cameras (whether full-frame or APS-C).

EF-S lenses: These are special EF lenses designed specifically for Canon's APS-C SLR cameras. They cannot be mounted on full-frame SLR cameras (because their rear lens

group will protrude and may damage the mirror of a full-frame camera), but can be mounted on Canon's EOS R series mirrorless cameras (with cropping) via an adapter.

Rich lens group: After years of development, the EF lens system has an extremely large lens group, covering from ultra-wide angle to ultra-telephoto, from fixed focus to

zoom, from macro to shift, and various special-purpose lenses, providing photographers with a great choice.

Built-in motor: EF lenses all have built-in focus motors (such as USM ultrasonic motors, STM stepping motors, etc.) to achieve fast, quiet and accurate autofocus.

Difference between EF lenses and RF lenses (Canon mirrorless camera lenses):

In recent years, Canon has launched a new RF mount lens, mainly for its EOS R series mirrorless cameras. The main difference between RF lenses and EF lenses is:

Mount design: The RF mount has a larger diameter and a shorter flange focal length. This makes lens design more flexible and enables the manufacture of more compact

lenses with better optical performance.

Communication speed: The RF mount has more electronic contacts and faster communication speed, making data transmission between the body and the lens more

efficient, which helps to achieve more advanced focus and anti-shake functions.

Control ring: RF lenses are usually equipped with a customizable control ring, which allows users to quickly adjust parameters such as aperture, ISO, shutter speed, etc.

Although RF lenses are the future development direction of Canon, by using a mount adapter (such as the EF-EOS R adapter), most EF lenses can still be perfectly used onCanon EOS R series mirrorless cameras, and can retain autofocus, anti-shake and other functions. This allows old users with a large number of EF lenses to smoothly

transition to the mirrorless system.