What is the standard lens focal length of 135 camera?

The standard lens of 135 camera is a 50mm focal length lens.

Usually the standard lens refers to the 50mm fixed-focus lens of a full-size camera, because the viewing angle feels like it is seen by the naked eye. More real.

Because the picture effect of standard lens is very similar to the visual effect of human eyes, the picture effect taken with standard lens is very ordinary, even very "dull", and it is difficult to obtain the artistic effect of rendering the picture like wide-angle lens or telephoto lens.

The visual effect of the standard lens has a natural sense of closeness, and the distance between the standard lens and the subject is moderate, so it is widely used in ordinary landscapes, ordinary portraits, snapshots and other photography occasions. The most common commemorative photos are taken with standard lenses.

Extended data:

The lens consists of several groups, about a dozen lenses. Fixed focus is different from zoom and lens focal length, which makes the lens have completely different optical design. The transmittance, curvature and optical path design of the lens largely determine the imaging quality of the lens. However, it should be noted that the quality of the lens is not directly proportional to the number of lenses.

The most representative ones are ultra-low dispersion lens (fluorite) and aspheric lens. Ultra-low astigmatism lens can effectively reduce and weaken the dispersion phenomenon that affects the photo quality.

Aspheric lens needs a special grinding process, and the curved surface of the lens is no longer spherical. Aspheric lens realizes the refractive power of the peripheral part by reducing the curvature of the peripheral part, and ensures that all points with different distances from the optical center have the same focus. This is the principle that aspheric lens can improve the imaging quality.