What do the parameters on the camera lens mean?

For example, "f = 7.8 mm-23.4 mm, 38 mm- 1 15 mm (equivalent to 35 mm)" on the lens means that the focal length of the camera is 7.8 mm-23.4 mm, and it has 3 times optical zoom capability. After conversion, the oblique angle of view is equivalent to 38 mm-1of the traditional 35 mm camera. Generally speaking, the standard lens focal length of a 35 mm camera is 28 mm ~ 70 mm, so if the focal length is higher than 70 mm, it means that the telescopic effect is supported, and if it is lower than 28 mm, it means that it has wide-angle shooting ability.

Detailed description of lens recognition

AI: automatic maximum aperture transfer technology. Published in 1977, used for manual lens. Logo does not appear in the lens name, and the smallest number on the aperture ring of AI lens is green.

AI-S: automatic shutter index transfer technology. Published in 198 1 for manual lens. There is no logo in the lens name, and the smallest number on the aperture ring of AI-S lens is yellow.

AF: autofocus technology. The AF in the name indicates that this is an autofocus lens, but the lens itself has no motor. If the body does not have a focus motor, it cannot focus automatically.

AF-I: 1992 lens has built-in motor and CPU contacts, which are mainly used for professional telephoto lenses. Has been replaced by af-S.

AF-S: autofocus lens with built-in SWM ultrasonic motor. This kind of lens can also achieve autofocus on low-end cameras such as Nikon D5 100/D3 100 without a body motor.

ASP: Indicates that an aspherical lens is used in the lens.

CRC: short-range error correction system. The system enables photographers to obtain excellent image quality when shooting at close range and increasing the focus range.

D: focal length data transmission technology. D-lens supports 3D matrix photometry.

DC: defocused image control. Nikon original lens can provide unique zoom control function. Its main feature is that it allows fuzzy control of the foreground or background of a specific object to obtain better defocus imaging.

DX: Special lens for APS-C camera, with small image field design, can't be used on Quan Huafu fuselage.

Ed: That means ultra-low dispersion lenses are used in the lens.

G: G lens cancels the traditional manual aperture ring. G lens often appears on Nikon's latest lens together with AF-S, showing an upgrading trend.

Macro: Macro lens.

N: It was once used to represent a new lens, but now the N with a hexagonal bottom on the lens means that the lens is coated with nanocrystals.

PC-Shift: move the lens.

Radio frequency: rear group focusing technology.

S: Thin, appearing on some thin lenses.

SIC: super composite coating.

TC: rangefinder.

VR: image anti-shake system. This shows that the lens has anti-shake function.

The logo on the lens

The logo on the general attack map is to know the focal length of this camera, the maximum aperture value and a series of information. A method of viewing camera lens.