A standard lens (or average) is one that reproduces the same field of view as the human eye. The subject is the same size through the lens as when it is seen with the naked eye. There is also no distortion. Standard lenses are no wide-angle or telephoto. The focal length for a 35mm film camera was 50mm.
The focal length of a wide-angle lens is significantly shorter than that of a normal one. The focal length of a 35mm film camera wide-angle lens was typically 35mm or 28mm. This lens lets you capture more of the scene, but it also simulates being closer to the subject.
Wide-angle lenses emphasize the differences in size and distance between objects. While objects closer to the subject appear more prominent, objects further away appear smaller. This can be used to make the foreground objects stand out and more striking while also capturing extensive backgrounds.
Wide-angle lenses can cause perspective distortion. Parallel lines tend to converge more. If the camera is pointed up from the ground, buildings may appear bent or fall backward.
Wide-angle lenses offer a comprehensive “depth of field.” They allow for more detail in the scene, which is a shorthand for more wide-angle lenses. The background will be likely to be sharply focused if the focus is on the subject closest to it.
Wide-angle zoom lenses are great for landscape, architectural and interior photography. These lenses are not meant to be used in place of moving closer to the subject.
Telephoto lenses can be broken down into two types: medium telephoto (85mm to 135mm for 35mm film format) and super-telephoto (355 mm to 315 mm in 35mm film format).
Telephoto lenses are most well-known for distant magnifying objects. A 100mm lens will magnify the subject twice in 35mm photography, where 50mm is the standard focal length. A 200mm lens will magnify it four times.
Telephoto lenses can be used to get closer to a subject (e.g., wildlife photography with a super-telephoto lens), but there are other optical effects that can also be applied, which may be different from those of wide-angle lenses.
Long lenses can appear to reduce the distance between objects, making them appear closer together. They are better at preserving parallels and do not make linear objects appear lean or bent.
Telephoto lenses have a smaller depth of field. This means that blurring of background is possible when the focus is on the subject. Because long lenses are easier to blur the background (defocus background in image to make a subject stand out), it is easier to use longer lenses.
Portrait photography is significant to the use of medium telephoto lenses, aside from the ability to get closer.
Portrait photography lenses are usually fast (I.e. They have large apertures and medium focal lengths of 85 to 135mm.
This focal length lens provides the best perspective distortion for portraits of the head and shoulders. Portraits taken with wide-angle lenses are more difficult to take because the perspective distortion causes noses to appear more prominent. Portrait lenses do the reverse.
Because they permit shallow depth of field (blurring background), fast, wide-aperture lenses are preferred. A large aperture can also produce a soft-focus effect. If the eyes are sharply focused, the ears and nose will appear slightly blurred and softened.
A zoom lens can be used to combine a wide-angle lens, standard lens, medium telephoto/portrait lens, and super-telephoto lens in one compact package. Each lens has its own purpose and features that can enhance certain scenes or subjects while degrading others. It is not intended to be used as a walking aid but rather to help the subject move towards or away.