Introduce what a wide-angle lens is and its function.

What is a wide-angle lens and what role does it play in photography? Let's take a look!

What is a wide-angle lens

Wide-angle lens is a photographic lens with shorter focal length, larger viewing angle, longer distance and smaller viewing angle than standard lens. Wide-angle lenses are divided into ordinary wide-angle lenses and ultra-wide-angle lenses. 135 camera's common wide-angle lens has a focal length of 38-24 mm and a viewing angle of 60-84 degrees. The ultra wide-angle lens has a focal length of 20- 13mm and a viewing angle of 94- 1 18 degrees. Because the wide-angle lens has a short focal length and a large viewing angle, it can shoot a large area of scenery in a short shooting distance. Therefore, it is widely used to shoot large-scale landscape photography.

Characteristics of wide-angle lens

The basic characteristics of a wide-angle lens are its large viewing angle and wide field of vision. The range of scenery observed from a certain viewpoint is much larger than that seen by human eyes at the same viewpoint; The depth of field is long, which can show a fairly clear range; It can emphasize the perspective effect of the picture, be good at exaggerating the foreground and express the sense of distance of the scene, which is conducive to enhancing the appeal of the picture.

In photography creation, shooting with a wide-angle lens can achieve the following effects:

1. can increase the sense of spatial depth of photographic images;

2. The depth of field is long, which can ensure that the scene before and after the subject can be clearly reproduced on the screen. Therefore, the vast majority of modern pocket automatic cameras (commonly known as fool cameras) use ordinary wide-angle lenses of 38-35 mm;

3. The lens covers a large area and has a wide range of scenes;

4. The scene shot at the same shooting distance is smaller than the scene image shot with the standard lens in the picture;

5. Perspective distortion and image distortion are easy to appear in the picture. The shorter the focal length of the lens and the closer the shooting distance, the more obvious this defect is.

Therefore, when shooting portraits, it should not be close to 0.6 meters to avoid perspective distortion. If you use ordinary wide-angle lens to shoot standard portraits for pasting files, it is best to shoot them in waist-length or knee-length images; When taking this portrait photo with a super wide-angle lens, it is best to take a full-length portrait first, and then cut it in the process of enlargement to get a standard portrait photo to avoid perspective distortion.

Of course, sometimes we can consciously use this perspective distortion to alleviate some defects of the subject's face when shooting portraits. If the subject has a narrow forehead and a wide chin, he can shoot with a slightly higher overlooking angle to offset the defects; On the other hand, low-angle upward photography can be used.

When shooting a full-length portrait with a wide-angle lens, there will still be distortion if shooting at a low angle, but sometimes this feature can be used to make up for some shortcomings of the subject. For example, some subjects' legs are shorter than their body length, and shooting at this angle will make their legs appear slender on the screen and increase the aesthetic feeling.

Shooting with a wide-angle lens will not only produce perspective distortion, but also produce edge distortion. This distortion is mainly caused by the oblique projection angle from the back of the lens to the edge of the film field of view. When shooting a group image, it is easy to make the subject on the edge of the picture short and fat.