Overview of infrared lens
In traditional digital cameras, a wide-angle lens is a photographic lens with a focal length shorter than a standard lens, a viewing angle larger than a standard lens, a distance longer than a fisheye lens, and a viewing angle smaller than a fisheye lens. (Infrared lens) Wide-angle lens is divided into ordinary wide-angle lens and ultra-wide-angle lens. The focal length of the ordinary wide-angle lens of the 135 camera is generally 38-24 mm, and the angle of view is 60-84 degrees; the focal length of the ultra-wide-angle lens is 20-13 mm, and the angle of view is 94-118 degrees. Due to the short focal length of the wide-angle lens and the large viewing angle, a larger area of scenery can be captured within a shorter shooting distance. Therefore, it is widely used in the shooting of large-scale photography works. In photography creation, using a wide-angle lens to shoot can achieve the following effects: one is to increase the spatial depth of the photographic picture; the second is to have a longer depth of field, which can ensure that the subject's front and back scenes are clear on the screen Reappear. Therefore, most modern pocket-sized 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 the shooting range is wide; fourth is the scenes shot at the same shooting distance , The image in the screen is smaller than that of a scene taken with a standard lens; fifth, the defects of perspective distortion and image distortion are prone to appear in the screen. The shorter the focal length of the lens and the closer the shooting distance, the more obvious this defect is. Commercial-grade digital cameras often use the same ordinary wide-angle lens as an ordinary 35 mm camera. Due to its advantages in depth of field and wide shooting range, when choosing a digital camera, a digital camera with the same performance (infrared lens) can have a wide-angle lens. And long-distance digital cameras will perform better.