When adjusting the aperture, the aperture is always at the maximum aperture state. Only when the shutter button is pressed to release the shutter, the aperture automatically shrinks to the adjusted f-factor, and the aperture returns to the maximum aperture after exposure.
The CCTV lens has two fingers in film and television. One refers to the optical components used by a movie camera and a projector to generate an image. It consists of multiple lenses. Various CCTV lenses have different modeling characteristics. Their application in photographic modeling constitutes a means of optical expression; a two-finger continuous picture taken from power on to power off, or between two splicing points. The fragment is also called a gimmick. One-finger and two-finger are two completely different concepts. In order to distinguish the two, the one-finger optical CCTV lens and the second-finger CCTV lens are often referred to.
The CCTV lens referred to in film and television is not a CCTV lens in a physical or optical sense, but a CCTV lens that carries an image and can form a picture. CCTV footage is the basic unit that makes up the entire film. Several CCTV shots constitute a paragraph or scene, and several paragraphs or scenes constitute a film. Therefore, CCTV lens like 4mm lens angle of view is also the basic unit of visual language. It is the basis of narrative and ideology. In the early shooting of film and television works, the CCTV lens refers to the sum of the uninterrupted footage captured by the camera from the start to the stationary period; in the post-editing, the CCTV lens is a group of pictures between two editing points; in the finished film, A CCTV lens is a complete segment from the previous optical transition to the next optical transition.
The main function of the CCTV lens is to collect the reflected light of the illuminated object and focus it on the CCD. The image projected on the CCD is inverted. The camera circuit has the function of inverting it. Its imaging principle is the same as that of the human eye.
CCTV lens classification: According to the CCTV lens manufacturer classification, mainly Japanese CCTV lens and German CCTV lens. Japanese CCTV lenses are mainly color reproducible, and German CCTV lenses have a strong sense of hierarchy. China's CCTV lens market has gradually occupied a certain market, mainly due to its relatively low price.