What are wide-angle lenses, medium-focus lenses and telephoto lenses? What are their functions? How to distinguish them? thank you

Wide-angle lens is a photographic lens with shorter focal length, larger viewing angle, longer focal length and smaller viewing angle than standard lens.

A long focal length lens refers to a photographic lens whose focal length is longer than that of a standard lens.

Medium focus lens: a lens with a focal length of 85 mm ~ 135 mm, and a lens with a focal length of 1.5 ~ 4 times that of the meter head.

Function:

Wide-angle lens: the perspective of wide-angle lens is exaggerated, showing obvious perspective effect and emphasizing the sense of distance. Widely used in news photography and landscape photography, it will have a strong visual impact.

Medium focus lens: The photos taken at this focal length have the smallest deformation, can correctly reflect the shape of the subject, and it is relatively easy to design into a super-large aperture.

Telephoto lens: Suitable for shooting distant objects.

Distinguish:

1, look at the focal length.

A lens with a focal length of less than 35MM is a wide-angle lens, a lens with a focal length of 85mm ~ 135mm is a medium-focus lens, and a lens with a focal length of 200MM or more is a telephoto lens.

2, according to the different imaging.

Wide-angle lens has a wider imaging range, telephoto lens has a smaller spatial depth of field and medium focal lens has the smallest deformation.

3. It depends on the angle of view.

Wide-angle lens has a large angle of view, telephoto lens has a small angle of view, medium-focus lens is no different from ordinary lens, and the angle of view is medium.

Extended data:

Shooting with a long focal length lens has the following characteristics:

1, small viewing angle

Therefore, the spatial range of the shooting scene is also small, and the shot image is larger than the standard lens at the same shooting distance, which is suitable for shooting the details of distant scenes and shooting inaccessible subjects.

2. Short depth of field

So you can highlight the subject in a messy environment. However, this brings some difficulties to accurate focusing. If the focus is slightly inaccurate when shooting, the subject will be blurred.

3. Poor perspective effect

This kind of lens has obvious characteristics of compressing spatial depth and exaggerating background.

References:

Baidu encyclopedia-telephoto lens

Baidu encyclopedia-teaching section