What Are the Different Types of Camcorders?

The digital camera actually refers to a digital signal processing camera, that is, the three primary color electric signals obtained by the photoelectric conversion device are still analog signals, but they are converted into digital signals in subsequent processing and a series of Digital processing technology ^[1] .

The video processing amplifier of the digital camera is divided into two parts, namely the analog processing part and the digital processing part.

The analog processing part mainly includes pre-amplifier, black spot correction, gain enhancement, white balance adjustment, white spot correction, stray light correction, black balance adjustment, pre-bending and so on. After the analog tri-color signals processed as described above are converted into 10-bit or 12-bit digital signals after analog-to-digital conversion.

The digital processing part mainly includes A / D conversion, data detection, contour correction, color correction, 1 correction, white compression, mixed blanking, white cutting, etc. After digital processing, digital component signals Y / R-Y / B -Y can be output. Directly used by digital component equipment, and can also output analog component signals and composite full TV signals after digital-to-analog conversion ^[1]

The composition and working principle of digital cameras are basically the same as analog cameras. However, digital cameras have some advantages that analog cameras do not have, such as high stability and reliability, and precise adjustment. More importantly, due to the use of digital processing technology, many tasks that cannot be completed in an analog camera can be achieved, which greatly improves the overall performance of the camera and also greatly improves the image quality ^[1]

Since the advent of digital cameras, the quality of recorded images has grown rapidly. With the increasing popularity of digital cameras, the frequency at which people use digital cameras has increased in various fields. There are many types of digital cameras. According to different uses and different classification methods, the digital cameras are classified in various ways.

• Classification by imaging quality

1. Broadcast camera This camera has very high image quality, realistic color tone reproduction, high adjustment accuracy and comprehensive working performance, but the price is relatively expensive. The SD broadcast-level pixel area is 720 × 576 (PAL), the transmission code rate is 50Mb s, and the HD broadcast-level pixel area is 1920 × 1080 (PAL), and the transmission code rate is 50Mb / s. Broadcast cameras are mainly used in the field of digital film shooting and broadcasting, such as the shooting of television stations, advertising companies and film and television production units.

2. Professional camera (also known as business camera)

Professional cameras are used in professional fields other than radio and television, such as education, military science and education propaganda, industrial production, and medical and health fields. This highlights the requirements of the camera to be lightweight and inexpensive. The image quality is lower than that of broadcast-only cameras. The SD pixel area is 720 × 576 (PAL). 1280 × 720 (PAL), the transmission code rate is 25Mb / s.

3. Civilian camera (also known as home camera)

Civilian cameras are used in applications where image quality is not high. For example, digital palm camera in DV format, SD camera area is 720 × 576 (PAL), HD can generally reach 1280 × 720 (PAL) transmission bit rate, and the horizontal resolution is about In the 500 TV line, the signal-to-noise ratio is about 50dB. This type of camera has the characteristics of miniaturization. For example, the SONY / PANASONIC / JvC palm camera series belong to this type, so it makes shooting under many special conditions possible. . Sports special effects camera, small camera head can be installed on the referee's protective mask; international motorcycle competitions, small camera can be installed on motorcycles, video from the athlete's point of view, etc., these have a certain role in the production of the program. In recent years, civilian cameras have gradually entered the field of high-definition, and the imaging quality has also developed rapidly. Another feature of civilian cameras is that they are the cheapest. Such cameras in our country are beginning to spread with the trend of thunder and lightning. Nowadays they are widely used in households, so they are called home cameras.

• Classification by program production

In the field of radio and television, according to the different production methods of TV programs, they can be divided into the following three types:

1. Studio ESP (ESP) camera ESP, or "Electronic Studio Production", which mainly refers to the studio

Production of video or live shows. The camera used in this production mode, the working conditions are very conducive to the acquisition of high-quality pictures, such as moderate illumination intensity, color temperature and other high-fidelity sound. Such as news studios, a variety show, etc., in order to improve performance indicators, usually use larger camera components. Therefore, they have the highest definition, the highest signal-to-noise ratio, and the best image quality. Of course, they are large and expensive.

2. Electronic news interview (ENG) camera ENG, that is, Electronic News Gathering. The production of programs in this way is characterized by the use of portable video and video equipment to collect TV news; the program is divided into two stages of pre-shooting and post-editing.

Due to the complex and changeable scene of news shooting, ENG cameras are generally small in size, light in weight, easy to carry, have good adaptability to non-standard lighting conditions, and have good performance in harsh environments (such as large-scale changes in operating temperature). Safety and stability, great convenience in the use of debugging operation (full automatic mode). They have slightly lower image quality than studio cameras and are relatively cheap.

3. Live Program Production (EFP) Camera

EFP stands for Electronic Field Production. The feature of producing programs in this way is that multiple devices are used simultaneously, including multiple cameras, switchers, mixers, and other auxiliary equipment (lights, microphones, video recorders, and vehicles); the signals are switched on-site to provide a continuous one-time signal The program can be broadcast live or recorded after the live production is completed; therefore, this program production method is highly lively. The working conditions of the EFP camera are between the two cameras mentioned above, and the performance indicators also take into account these two aspects. Their image quality is similar to the cameras used in studios, but they are smaller in size and can meet the needs of portable live program production.

• Classification by number of camera components

The three-camera camera imaging unit is composed of three imaging device chips. The light is taken into the three primary colors (red, green, and blue) by a prism, and they are input into different imaging devices. Large light collection area, and the red, green and blue information obtained by each imaging device is the information carried by the incident light itself. Therefore, the image formed by this method has high quality, good color reproduction, and high definition and signal-to-noise ratio. Most professional and broadcast cameras use this method. Although the three imaging devices successfully solved the problem of color separation, it was not perfect. First, it must have a prism, which makes it difficult to reduce its volume. If the size of the imaging device is to be increased, the size of the prism must also be increased. And the prism itself is an optical device, its optical distortion will directly cause the picture distortion. This natural obstacle makes it difficult for three-chip imaging devices to achieve large-sized imaging frames. At present, the maximum format of the three imaging devices is 2 / 3in, and the effect and cost are unacceptable. This is why the camera of the three-chip imaging device is relatively large, and it is also the reason why the three-chip imaging device is only applied to the camera and cannot be applied to the camera.

2.Single-chip camera

The camera uses an imaging device chip, and only one image is imaged on the imaging device. The signals reflecting the three primary colors RGB are reproduced by using a Bayer array filter on each pixel and a specific signal processor matched by the filters. However, the conversion from Bayer array colors to primary colors must be performed by a digital camera, and the interpretation process will cause color errors. So the image quality of traditional single-chip cameras is average, and it is mostly used in non-professional fields.

• Classification by level of integration

Integrated camera

An integrated camera is a device that integrates a camera and a video recorder, as shown in Figure 1.12. The camera unit and video recording unit of this type of camera cannot be separated.When working, the process of converting optical signals into electrical signals (camera process) is completed, and finally the electrical signals are converted into magnetic signals and recorded on the record carrier (recording process) . The integrated camera is also called the camera-recorder-player.

2. Detachable camera

The detachable camera is a camera with a camera adder, which can be used as a separate camera. For example, in the variety show produced by the ESP method, there are multiple cameras in each variety show. Each camera can be not equipped with a video recording unit. It only needs to be recorded by the video recorder at the switcher. It can also be used as a camcorder with a separate portable video recorder, so that different formats of video recorders can be used due to the different needs of program production.

• Five, according to the size of the camera device

The size of the imaging device is directly related to the quality of the image. Under the same manufacturing process, the larger the size, the more effective pixels, the better the image sharpness, and the sensitivity will be improved. Of course, the camera volume will also increase.

Classification by storage medium

Tape camera

A tape camera is a camera that uses a tape as a storage medium to store moving images. Due to the different video formats of tape cameras, different types of tapes are used. Use different tape formats based on different requirements.

2. CD camera

This type of camera uses an optical disc as its storage medium. Rewritable DVD discs, etc. The storage media of civil DVD digital video cameras (disc-type DV) use DVDR, DVR + R, or DVD-RW, DVD + RW to store dynamic video images.

The biggest advantage of the home DVD digital video camera is "shoot and play", which can quickly play on most DVD players. The disadvantage is that the price of DD discs is slightly higher than that of tape DV.

3. Hard disk camera

4. Memory Card Camera

The camera saves power, has a small size, uses less consumables during video recording, facilitates later editing, and has stable working conditions. ^[2]