What are the uses of SLR camera lenses?

The lens determines the quality of the photo to a certain extent, whether it is sharp, vivid, accurate in color and correct in geometric proportions.

The quality of the photo taken depends largely on the lens, not the body. There is only one photosensitive element in the fuselage. The difference between photosensitive elements of the same size is very limited. The main difference is the lens.

Another very important element of the lens is the focal length and aperture. The focal length determines the viewing angle, and the aperture determines the amount of light. A good lens provides the camera body with sharp, vivid images, accurate colors, and correct geometric proportions.

The lenses are mainly divided into the following types:

The first type is the wide-angle lens. A wide-angle lens in this sense refers to a lens with a focal length below 35mm, such as a 28mm, 24mm or even a 16mm lens.

The second type is the standard lens. Generally speaking, the focal length is 50mm or 85mm.

The third type is a medium telephoto lens, usually 100mm or 135mm. Among them, the 100mm lens is generally a macro lens, the 135mm lens is also a portrait lens, but it focuses on half-length portraits, and the 85mm focuses more on full-body portraits.

Those with focal lengths above 200mm are what we call telephoto lenses. Telephoto lenses are very versatile and can be used to shoot landscapes and portraits.

Extended information:

When taking pictures, the reflector will pop up immediately, the lens aperture will automatically shrink to a predetermined value, the shutter will be opened to expose the film to light, and after the exposure is completed, the shutter will be closed to reflect the light. The mirror and lens aperture are reset at the same time. This is the SLR technology in the camera.

SLR, equivalent to single lens reflex. The camera using this technology has only one lens, which is used for both photography and framing. This can fundamentally solve the problem of photo quality degradation caused by parallax.

When using a SLR camera to view the view, the object being photographed will be very clear. It will be reflected by the oblique reflector onto the focusing screen to form an image, and then reflected by the "roof prism" with a ridge on the top, thus framing and focusing. All very convenient.

Baidu Encyclopedia-SLR camera lens