Definition
Professional camcorders refer to a category of camcorders that are video recorders and playback devices.The DVCAM format is a video and audio storage medium developed by Sony in 1996, whose performance is almost exactly the same as that of DV, but differs in the width of the two traces, which is 10 micrometers wide for DV and 15 micrometers wide for DVCAM. Since the recording speed is different, DV is 18.8 millimeters per second, while DVCAM is 28.8 millimeters per second, so the two are also different in recording time, DV tape is 60-276 minutes of video and audio, while DVCAM tape can record 34-184 minutes.
Specifications
In terms of video and audio pickup, DV and DVCAM are basically the same, with a recording bit rate of 25Mbps, and two sampling modes of 48kHz and 32kHz for audio, both of which can be downloaded to a computer for non-editing via IEEE1394 FireWire.
DVCPRO is a new digital format introduced by Panasonic in 1996 based on the DV format. It uses 4:1:1 sampling, 5:1 compression, and an 18-micron trace width. 1998 saw the introduction of DVCPRO50, based on DVCPRO, which uses 4:2:2 sampling and 3.3:1 compression.
The DVCPRO digital camcorder all weighs just over 5 kilograms, which is very lightweight and particularly suitable for news use, as it uses a DV format 1/4-inch cassette tape compatible with the home DV format, which lays the foundation for a wide range of news sources.
Surveillance camera security system, image generation is currently mainly from the CCD camera, definition
CCD is a charge-coupled device (Charge Coupled Device) for short, it can change light into charge and charge storage and transfer, but also can be stored out of the charge to make the change in voltage, and therefore is the ideal camera! Therefore, it is an ideal camera component, and the CCD camera composed of it has the characteristics of small size, light weight, not affected by magnetic field, and anti-vibration and impact, and is widely used.
Classification
CCD cameras can be broadly divided into the following categories:
Divided according to the color of the image
1. Color camera: for the scene of the fine discrimination, such as the identification of clothing or the color of the scene. Because of the color and make the amount of information increased, the amount of information is generally considered to be 10 times the black and white camera.
2. Black-and-white camera: is used in poorly lit areas and areas where lighting can not be installed at night, only to monitor the location or movement of the scene, you can choose a black-and-white camera resolution is usually higher than the color camera.
Divided according to the camera resolution
1. Image pixels in the 250,000 pixels (pixel) or so, color resolution of 330 lines, black and white resolution of about 400 lines of low-grade type.
2. Image pixels between 250,000 ~ 380,000, color resolution of 420 lines, black and white resolution of 500 lines of mid-range
Divided according to the sensitivity of the camera
1. Ordinary type: normal work requires illumination 1 ~ 3 LUX (lux)
2. Moonlight type: normal work requires illumination 0.1 LUX or so.
3. Starlight type: the illumination required for normal operation is 0.01 LUX or less
4. Infrared illumination type: in principle, can be zero illumination, using infrared light source imaging.
Divided by the size of the CCD target surface of the camera element
1. 1in target surface size of 12.7mm wide X 9.6mm high, 16mm diagonal
2. 2/3in target surface size of 8.8mm wide X 6.6mm high, 11mm diagonal
2. 1/2in target size of 6.4mm wide X 4.8mm high, 11mm diagonal
2. 1/2in target size of 6.4mm wide X 4.8mm high, 4.8mm diagonal
2. 4.8mm, diagonal 8mm
4. 1/3in target size is 4.8mm wide X 3.6mm high, diagonal 6mm
5. 1/4in target size is 3.2mm wide X 2.4mm high, diagonal 4mm
6. 1/5in is in the process of development, and has not yet been launched the official product
Additionally CCD camera PAL and NTSC system, but also by the image signal processing mode or by the camera structure.
Principle of operation
The working principle of the CCD is: the subject reflected light, spread to the lens, the lens focus to the CCD chip, the CCD according to the intensity of the light accumulates the corresponding charge, by the periodic discharge, resulting in the production of electrical signals that indicate a picture, filtered, amplified processing, through the camera's output terminal output a standard composite video signal. This standard video signal is the same as the home video recorder, VCD player, home video camera video output is the same, so you can also be recorded or connected to a television set to watch. Definition
The network camera is a combination of traditional video cameras and network technology produced by a new generation of cameras, it can be transmitted to the other side of the world through the network image, and the remote viewer does not need to use any professional software, as long as the standard Web browser (such as "Microsoft IE or Netscape) can monitor its image.
Market demand
Network cameras are undoubtedly the first major theme in the field of video surveillance. On the one hand, the rapid development of electronic and network technologies has greatly enhanced the application value and scope of standard zoom lenses; on the other hand, the rapid expansion of the global security needs and the increasing use of user requirements has also greatly stimulated the development of network cameras. The new generation of webcams combines traditional webcams with the new generation of webcams produced by network technology. As long as the webcam is plugged into a network cable, it can be used without the need of a computer, without the need of a video capture card, without the need to monitor the local limitations of the webcam, it can be used to monitor the webcam from anywhere and support 12 clients to monitor the webcam at the same time.
Introduction
The webcam can rotate 320 degrees left and right, 60 degrees up and down to monitor, take pictures and videos of the screen, and send the pictures and videos to email or FTP server. The camera has a motion detection function and can be set to send an e-mail alert. Enhanced version can easily realize the low network bandwidth transmission of high-definition images, the image is clearer than the ordinary version of the camera, and realize the new features such as night vision, audio transmission, dynamic alarms, alarm time zone can be set, automatic recovery from anomalies, automatic connection after network interruption and so on. 1. Broadcast Camera: Broadcast Camera is generally used in television stations and production centers, its quality requirements are high, such as clarity 700-800 lines, signal-to-noise ratio of 60dB or more, from the lens to the camera devices, circuits, etc. are superior, of course, its price is quite amazing, generally more than 100,000 yuan, such as BVP-70P, DV-700P, and so on.
2. Business-class cameras: business-class cameras are generally used in the education sector of the electronic education and industrial surveillance systems. Its performance indicators are also relatively good, the beginning of a single tube (such as DXC-1640), double tube (DXC-1800), mostly three tubes (DXC-M3A) or three CCDs (such as DXC-3000P, DXC-6000P, DXC-M7, DXC-537) price is relatively low, the education sector can afford, generally less than 100,000 yuan.
3. Home-level camera: this grade of the camera a wide variety of main features are small size, light weight, multi-functional, easy to use and operate, inexpensive, generally in the 10,000 yuan or so. Its quality level than the broadcast level or business level, more than a single CCD camcorder. In the teaching also often use this grade level of the camcorder to produce programs or carry out micrographics teaching.
So far it has developed to four recording formats:
VHS-C NV-G200 NV-G300
①VHS S-VHS M8000 M9000
S-VHS-C NV-S700
VHS (VIDEO HOME SYSTEM) was jointly published by the Japanese JVC Corporation and others in 1976. Japan's JVC Corporation and others. The representative models are M5, M7, M1000, M3000, etc. In 1982, the VHS-C type camcorder was released, due to the reduction of the size of the tape used, the overall size of the camcorder was reduced, and it was easier to carry on traveling. 1987, the S-VHS type high-tape camcorder was released, with a clarity of 400 lines. Subsequently, the S-VHS-C camcorder, a compact high-bandwidth camcorder, was also released.
②β→ED-β (500 lines)
The β-type camcorders and video recorders were developed by Japan's SONY and others, and were not popularized and developed in China because their video recorders were defeated by VHS in the competition.
③8mm→Hi8
The 8mm camcorder and VCR was developed by SONY in Japan and published in 1984. The width of the tape is 8mm (1/3 inch), due to the reduction in the size of the tape, and the size of the cassette tape, and thus the size of the camcorder is greatly reduced, known as the palm of the hand. In 1989, the Hi8 type was released, which is a high tape of 8mm and is called "Super 8".
4DV Format
The DV format was originally developed by 55 manufacturers in Japan and around the world as the "Digital Video Recorder Specification for Consumer Use," or "DV Format" for short. A 6 mm (1/4 inch) wide tape is used, and the luminance and chrominance signals are recorded separately using a digital compression method. The clarity is up to 500 lines. The price is usually around 20,000 yuan.
This format has developed two professional grade level video recording format. That is, the DVC-PRO format represented by Panasonic and the DVCAM format represented by SONY. The price of the camcorder is about 100,000 yuan. (1) Studio/live seat type camera.
Seat machine type camera is larger, more bulky, usually mounted on a base or tripod to operate. Lens size, focal length range, relative aperture is also large.
Commonly used in studios, or other locations relatively fixed, these cameras are generally broadcast-quality.
(2) Portable cameras.
Small size, light weight, easy to carry, with a tripod or human body support shooting can be. Generally use DC battery power supply, can also be AC power supply through the AC combiner.
Can be used in a variety of occasions, such as electronic news interview (ENG) and electronic field production (EFP).
These cameras are shoulder-held, weighing 3-10 kilograms, and are generally broadcast or business grade. Handheld, weighing in at 0.7-3 kilograms, are home-based.
The development trend and the combination of video recorders to become an integrated camera. Use more flexible and convenient. For example: DXC-537 + PVV-1AP → PVW537.
Spectral range
(1) black and white camera: for monitoring subtitles, or industrial surveillance.
(2)Color camera: the most widely used.
(3) Infrared camera: night surveillance.
(4) X-ray camera: medical, security checks. 1. Social security surveillance cameras: large market, wide demand.
2. Unsuitable for exposed occasions: reporters unannounced visits to the camera, button to see the word camera (also known as wireless audio and video transmission system).