A camera is a device that uses optical principles to record images. The invention of the camera was originally used for the production of movies and TV programs, but now it has become popular. Just like cameras, early cameras needed to use negatives (that is, video tapes) for recording, but now the invention of digital cameras enables images to be directly stored in flash memory. The newer camera directly stores the image data in the hard disk of the fuselage, which can not only record dynamically, but also shoot statically, so it is not necessary to bring a digital camera at the same time. Family-style portable camera is light and easy to operate, and it is almost a necessary electrical appliance for families. Chinese name: camera mbth: Camera Inventor: Jules Janssen Classification: Description of high-speed cameras: Modern cameras have been born since 1872. Historical background, classification, high-speed cameras, aerial cameras, animation cameras, network cameras, home cameras, camera movements, definitions, main methods, frequently asked questions, The shot image of achromatic color is blurred, and the quality of the shot image is poor. One day in 1872, in a hotel in California, Leland Stanford and Cohen had a fierce argument: Did the horses all touch the ground when they were running? Stanford thinks that a running horse's hooves are empty at the moment of leaping; Cohen, on the other hand, thinks that a horse always touches the ground when it runs. No one could convince anyone of the result of the dispute, so they took the usual way of betting to solve it. They invited a good horse trainer to make a ruling, however, it was difficult for the referee to judge who was right and wrong. This is normal, because it is really difficult to see how the fast-running horseshoe moves with human eyes alone. So the rich man invited Edward McBride, an English photographer, to do the experiment. McBride connected the shutters of 24 cameras with 24 wires. In a very short time, he made the cameras take 24 photos in turn, and then read them one by one in order to observe how the horse jumped and landed. For this experiment, McBride and his assistants suffered a lot, paid a lot of labor, and it took six years to finally shoot a set of valuable information about the "horse running trail", which also confirmed Cohen's prediction was correct. However, McBride's success has raised a new problem to people: how to solve the problem of continuous photography, because he can only shoot a part of the galloping horse with 24 cameras. If the galloping horse runs a long distance of one kilometer, it will take thousands of cameras, and the length of the film will circle the earth once. Therefore, how to use a single-lens camera instead of a multi-lens camera or a group of cameras has become a key problem to solve continuous photography. In 1874, Jules Jean-Sang of France invented a camera. He wound the photosensitive film on a toothed film supply tray. Under the control of a pendulum mechanism, the film supply tray made intermittent film supply movement in a circular film supply box, and at the same time, the pendulum mechanism drove the shutter to rotate. Whenever the film stopped, the shutter opened for exposure. Janssen connected this camera to a telescope, which can take a set of photos of the planet's movement at the speed of one per second. Janssen named it a photographic gun, which is the ancestor of modern movie camera +Y6R. In 1882, when McBride traveled to Europe with his own continuous photos, their achievements greatly encouraged the French scholar Male. After several years of unremitting efforts, he used the principle of revolver to create a portable "camera gun", which was the first one that could be shot from one lens. A camera that takes several negatives in one second really solves the problem of continuous photography, which shows that modern cameras and photography technology have been born. In the same year, Jules Marie of France invented another new camera, which can shoot the coherent movements of birds, thus giving birth to photography technology. This photographic device is shaped like a gun. A round box like a large magazine is fixed at the trigger, and a large caliber barrel is mounted in front of it. A glass-sensitive optical disc coated with silver bromide emulsion is installed in the round box. When shooting, the photosensitive disc makes intermittent circular motion, and the shutter is coaxial with the photosensitive disc, and keeps rotating, blocking and absorbing the light beam through the lens. The whole machine is driven by a clockwork. You can take pictures at a frequency of 12 pictures per second with an exposure speed of 1/1 second. In 1888, Marley invented a new camera. He replaced the fixed photosensitive disc with a photosensitive paper tape wound around the shaft. When the photosensitive paper tape passed through the focus of the lens, two color grasping mechanisms fixed the photosensitive paper tape to expose it. Later, Marley replaced the photosensitive paper tape with photosensitive film. Marley's camera has been continuously improved, and finally it can shoot at a frequency of 6 shots per second on 9 cm wide film. Camera In 1889, Edison in America invented a camera. This camera uses a pointed tooth roller to drive the 19 mm wide non-perforated adhesive tape, and under the control of the ratchet wheel, it drives the adhesive tape to move intermittently and punch holes at the same time. This camera is driven by a motor, and the shutter shaft is linked with a phonograph, which records the sound when the camera is running. On this basis, a moving camera was invented. There is a cross wheel mechanism in the camera to control the film to move intermittently, and another gear drives the film to move forward. The camera uses 35 mm film with holes. In 1891, Edison obtained a patent for this kind of moving camera. The camera is classified into high-speed cameras and optical photographic instruments that record the images of moving objects at high speed. It records the flying attitude and events of Harmony at a high photography frequency. Intermittent and compensated high-speed cameras are often used in flight tests of rockets and spacecraft. The film of intermittent high-speed camera is controlled by the film grabbing mechanism, and the film does not move when shooting, and the exposure is controlled by the shutter. After exposure, the film moves by one frame. The film of the compensated high-speed camera is in continuous motion. When shooting, the target and the film are kept relatively still by the compensation mechanism, and the exposure is controlled by the shutter. Intermittent camera is used to photograph the rocket ignition, flame condition, plug falling off, longitudinal and lateral drift when the rocket leaves the frame, etc. The shooting frequency of the 35mm synchronous intermittent camera is not more than 3 frames per second. The shooting frequency of the compensated high-speed camera is from several hundred to several thousand frames per second, and it is continuously variable. It is used to shoot the secondary ignition and stage separation of the rocket, and also used to shoot the encounter of the rocket. High-speed camera is composed of optical system, shutter, film conveying and taking-up mechanism, frame and time control mechanism, etc. It can be fixed or mounted on a tracking frame to photograph flying targets manually or automatically. Camera aerial camera A camera mounted on an airplane to shoot vertically to the ground for drawing and surveying. Use the film, mostly in 24*24 cm images, and shoot with a 15 mm wide-angle lens. In addition, there is a multi-spectral camera with four lenses attached to the camera body for making composite color photos from a certain photo. Animation camera A camera equipped with a pause motor, which can shoot in a single frame. When shooting, it can move vertically on an animation stage to change the size of the photographed image or produce a zoom effect. Network camera connects the general camera to the switch or router with a network cable, and the manager can check the camera situation through the local area network or INTERTNET network. Independent webcam, which can be used without a computer, has the characteristics of simple installation and diversified functions. The built-in management web page can operate independently without a computer, and IE browser can be used to capture or store remote real-time images. The standard network plug RJ-45 interface is adopted, which has the function of license security verification, and more functions can be realized with software. Another way is to connect to wireless AP or wireless router directly with other standards such as 82.11g or 82.11b without network connection. The camera's home camera shoots all the actions of a paragraph with a distant view or moving lens. After the shooting, if only one camera is used, it is necessary to insert the repetitive actions of the middle scene and the specific shooting into the main shot during editing. The definition of camera motion refers to the motion of a movie camera, which aims to follow an action or change the presentation of the scene, people or objects being photographed. Main ways of camera 1. Push the lens in two situations: a. The camera moves forward along the optical axis; B, take a zoom lens, from the short focal length to the long focal length. The differences between the two methods are as follows: ① Zoom lenses often have emphasis. ② The main feature of zoom lens is subjectivity, while the main feature of camera moving forward is objectivity. The function of pushing the lens: ① bringing the audience into the story environment; (The camera moves forward) ② Protrude the subject (person or thing) from the numerous subjects; (3) Highlight the expressive force of the performance of a certain part of a character's body, such as face, hands and eyes. (4) emphasize and exaggerate the part of a subject. (zoom lens) ⑤ represents the subjective line of sight of the characters in the play. (Zoom lens) ⑥ Express the inner feelings of the characters. (Zoom lens) French Lieutenant's Woman, Meeting by the Sea. 2. Two situations of pulling the lens: A. The camera moves backward along the optical axis; B, take a zoom lens, from the long focal length to the short focal length. The difference between the two methods of camera: ① zoom lens often has emphasis. ② The main feature of zoom lens is subjectivity, and the main feature of camera retreat is objectivity. The function of zoom lens: ① to show the relationship between the subject and its environment; (2) ending a paragraph or ending the whole film. 3. Shake the lens When shooting a lens, the camera position does not move, only the body rotates up and down, left and right. The "shake lens" is divided into three categories: ① pure descriptive shake lens; (2) Expressive panning: Based on a certain skill photography, it expresses a person's impression or thought, such as the panning of a tree in Flying in the Wild Goose. ③ Dramatic panning. The main functions of shaking the lens are: ① introducing the environment. ② Turn from one subject to another. Camera ③ shows the movements of characters. ④ Represents the subjective sight of the characters in the play. ⑤ Express the inner feelings of the characters in the play. 4. The moving lens camera moves in all directions along the horizontal direction. ("Up" and "Down" are vertical directions). Two situations: a, people don't move, photography is mobile; B, people and cameras are moving. Close to "follow", but at a different speed. 5. Follow-up camera The camera moves with the subject. The difference between "following" and "moving" is as follows: ① The moving speed of the camera is consistent with the moving speed of the subject; ② The position of the subject in the picture composition is basically unchanged; ③ The scene of picture composition remains unchanged. 6, still lens should establish a big concept of movement. Under this concept, "still lens" is also a kind of film movement. Such as the still shot of Birdman. Such as the still depth of field lens of city of sadness. Finally, it needs to be explained that in the actual shooting of a film, pushing, pulling, shaking, moving, following and still are often used synthetically. They should not be strictly separated. Frequently asked questions: The specific performance of the photographed image achromatic color is that all the pictures are turned into black and white images. There are several main reasons for achromatic color's failure: (1) The camera is badly focused. Because of defocusing, the chroma signal of 4.5 MHz is lost, and the image clarity is also seriously reduced and blurred. It is important to check the focusing and current stabilizing circuit on the camera auto-focusing circuit board. (2) The gain amplifier stage of the chroma signal is turned off, and as a result, the chroma signal has no output. Emphasis should be placed on checking all levels related to gain amplification in the chroma signal channel, such as input and output amplification stages, automatic chroma control stages, buffer amplification stages, etc. (3) The chroma signal is interrupted. The reason is that the signal transmission line is open or the signal is short-circuited into the ground, so that the camera only outputs brightness signals, and the focus of inspection should be on the chroma channel integrated circuit. The camera image is blurred. This fault can be divided into two specific situations. One is simply that the image displayed by the viewfinder is blurred. Another situation is that the image output by the camera is blurred (at this time, the image displayed by the viewfinder must be blurred). For the first case, that is, the viewfinder image is blurred, the main reason is the focus voltage imbalance of the viewfinder. The solution is to readjust the focusing voltage. There are several solutions to the image blur output by digital camera: (1) The lens of digital camera is not clean. Just wipe off the dirty things. (2) The focal length is not adjusted properly. Especially when the digital camera is in manual FOCUS adjustment, the AUTOmatic focus function does not work, and the focus switch should be set to the auto position; In addition, if the shooting conditions are not suitable for automatic FOCUSing, the focus switch can be set to the MANUAL position, and the image can be restored to a clear state by manually adjusting the focus; (3) It is the fault of the camera circuit, which is mainly manifested in the poor focusing performance of the lens unit. At this time, we should focus on checking the focusing current stabilizing circuit. The poor quality of the shot image is mainly manifested in poor definition, false color and fixed spots on the picture. In this case, after the failure of the focusing circuit mentioned above is eliminated, the main reason should be the poor quality of CCD sensor. The sensor's pre-video output waveform can be observed by oscilloscope, and the sensor's poor performance can be determined after troubleshooting related peripheral components. The reason for the poor quality of the shot image is not only the fault of the camera, but also the fault of the video recording part, such as the pollution or damage of the magnetic head, or the fault of the relevant circuit.