Types, characteristics and uses of commonly used lenses?

Wide-angle lenses can be roughly divided into two categories: ordinary wide-angle lenses and ultra-wide-angle lenses. The focal length of ordinary wide-angle lens is between 24 mm and 45 mm; The focal length of ultra-wide-angle lens is generally less than 24mm, and there is a special lens called fisheye lens, which has a focal length of only a few millimeters.

Photographers usually rely on the short focal length and long depth of field of wide-angle lenses to bring the whole scene from near to far into a clear range of expression when shooting a wide scene. In addition, when shooting with a wide-angle lens, if a smaller aperture is used at the same time, the depth of field of the scene will become longer.

2. Medium focal length lens

The focal length of the medium focus lens is between 50mm- 135mm, including many commonly used focal lengths: 50mm standard lens, 85mm portrait lens, 100mm macro lens, 135mm portrait lens, etc.

Usually, the visual angle of the human eye is about 50, so people call the lens close to the portrait visual angle in the traditional 35mm camera a standard lens, and its focal length is 50mm, which extends to the zoom lens. As long as the focal length covers the 50mm zoom lens, it is generally called a standard zoom lens.

The standard lens is very close to the effect seen by human eyes, and the picture can give people a more realistic feeling, which can be used to shoot almost any scene and theme.

Because the standard lens is widely used, the first lens that many people buy is a standard zoom lens, and the second lens is a 50mm fixed focus lens.

3, telephoto lens

A telephoto lens refers to a lens with a focal length greater than 200mm, which is divided into telephoto lenses and ultra-telephoto lenses. The telephoto lens has a focal length of 200~300mm, which is suitable for shooting close-ups and stages. The ultra-telephoto lens has a focal length of more than 400mm, and is often used to shoot inaccessible birds, wild animals, large-scale stadiums and so on.

Extended data

Lens structure:

(1) Number of lenses: The combination of various types of lenses can reduce the color shift and improve the focus, but it will reduce the light transmittance.

(2) Lens transmittance: A good lens transmittance is good and expensive, and a poor lens will block light from passing through.

(3) Coating and grinding: The coating and grinding process of lenses affects the quality of lenses.

(4) Mechanical device: The accuracy of the internal mechanical structure of the lens affects the accuracy and reliability of the lens movement. Bad mechanical structure will produce adjustment errors and inconsistencies.

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