Angular resolution of wide angle lens

1800Hz.

A wide-angle lens is a photographic lens with a focal length shorter than a standard lens, a wider angle of view than a standard lens, a longer distance than a fisheye lens, and a smaller angle of view than a fisheye lens. Wide-angle lenses are divided into two types: ordinary wide-angle lenses and ultra-wide-angle lenses. The focal length of an ordinary wide-angle lens for a 135 camera is generally 38-24 mm, and the viewing angle is 60-84 degrees; the focal length of an ultra-wide-angle lens is 20-13 mm, and the viewing angle is 94-118 degrees. Because the wide-angle lens has a short focal length and a wide viewing angle, it can capture a larger area of ??scenery within a shorter shooting distance. Therefore, it is widely used in shooting large-scale style photography.

In photographic creation, using a wide-angle lens to shoot can achieve the following effects: First, it can increase the spatial depth of the photographic image; Second, the depth of field is longer, which can ensure the scenery before and after the subject. It can be reproduced clearly on the screen. Therefore, the vast majority of modern pocket automatic cameras (commonly known as point-and-shoot cameras) use ordinary wide-angle lenses of 38-35 mm; third, the lens covers a large area and can capture a wide range of scenery; fourth, the scenery photographed at the same shooting distance , the image in the picture is smaller than that of the scenery shot with a standard lens; fifth, defects such as perspective deformation and image distortion are prone to occur in the picture. The shorter the focal length of the lens and the closer the shooting distance, the more significant this defect will be.

Therefore, when taking portraits, it should not be closer than 0.6 meters to avoid perspective distortion. If you use an ordinary wide-angle lens to take standard portrait photos for ID cards, it is best to take them at half waist or knee height. Like; when using an ultra-wide-angle lens to take such portrait photos, it is best to take a full-body image and then crop it during the magnification process to obtain a standard portrait photo, so as to avoid perspective distortion. Of course, sometimes when taking portraits of people, in order to reduce certain defects on the subject's face, this perspective distortion can also be consciously used. If the subject has a narrow forehead and a wide chin, a slightly higher overhead angle can offset the shortcomings; otherwise, a low-angle shot from above can be used. When using a wide-angle lens to shoot a full-body portrait, if you shoot at a low angle, distortion will still occur. However, sometimes this feature can be used to make up for some shortcomings of the subject itself. For example, some subjects have shorter legs and upper body. Longer, shooting at this angle will make the legs appear slender in the picture, increasing their beauty. Shooting with a wide-angle lens will not only produce perspective distortion, but also edge distortion. This distortion is primarily caused by the oblique projection angle from the rear of the lens to the edge of the film's field of view.

When shooting group portraits, it is easy for the subjects at the edge of the screen to become chunky