How Do I Choose the Best Professional Video Camera?

Cameras are roughly divided into three categories in the industry, namely broadcast, professional and home. China's broadcasting system is the PAL system (PAL system is a method of color coding in television broadcasting. The full name is Phase Alternating Line, phase inversion, 625 scanning lines, 25 frames per second, interlaced scanning). The standard picture should be 768x576 pixels. The current resolution of digital capture processing is generally 720x576. How does a broadcast camera differ from a professional and home camera? To comprehensively analyze the differences between them, there is too much content in terms of technical parameters, and it is difficult for ordinary people to understand the professional vocabulary inside.

Broadcast Camera

Cameras are roughly divided into three categories in the industry, namely broadcast, professional and home. China's broadcasting system is the PAL system (PAL system is a method of color coding in television broadcasting. The full name is Phase Alternating Line, phase inversion, 625 scanning lines, 25 frames per second, interlaced scanning). The standard picture should be 768x576 pixels. The current resolution of digital capture processing is generally 720x576. How does a broadcast camera differ from a professional and home camera? To comprehensively analyze the differences between them, there is too much content in terms of technical parameters, and it is difficult for ordinary people to understand the professional vocabulary inside.

I. Adjustment: (Applicable to equipment that is shared and not used by special persons)

First check the viewfinder display for standard, gain switch, aperture, and shutter setting status and position.

1. Hit the ** strip generator and adjust the contrast between the light and dark of the viewfinder in order to get the real standard TV image, and prepare for the later shooting work.

Experience: The performance of the viewfinder directly affects the photographer's judgment of the scene. After the experienced person turns on, he knows whether the viewfinder is standard. Beginners adjusting the viewfinder can not only cultivate good working habits, but also find problems in time to facilitate work. Need to adjust brightness, contrast, sharpness.

2. The initial standard of the gain switch is: 0dB. In the case of the largest aperture, the slowest shutter speed, and insufficient light input (low illumination), you can turn on the gain switch by 3dB, 6dB, or even more.

Experience: If objective conditions permit, try not to use the gain switch. Although the brightness of the picture has increased, the signal quality has decreased. Because, the noise is also amplified at the same time.

3. The iris has an automatic iris and a manual iris. The automatic iris is driven by a motor and automatically scales as the external light changes. Those with little experience often like the auto iris, which saves you worry and effort, so don't worry about forgetting to adjust. The manual iris can be adjusted freely subjectively according to the shooting intent, without being affected by the outside world.

Experience: Although the automatic iris is convenient and safe, it will be used in situations such as changes in light and darkness. Automatic zoom (such as panning). This affects the picture quality and affects the mood of the audience. In addition, when the camera is aging, the auto iris may be shaken, causing the picture to flicker. The manual iris is particularly important in shooting backlighting, intentionally lowering or increasing the brightness of the picture. When shooting a sports lens, the brightness of the object may change significantly. We can take the intermediate value of the aperture between the fluctuation and the fall or use a manual gradual adjustment method, and slowly increase or decrease the aperture when the audience cannot detect it. In order to obtain the screen brightness always remains stable.

4. The standard shutter speed is: 1/60 second. In normal shooting work, it is enough. Generally the highest is: 1/2000 second. Increasing the shutter speed by one level and attenuating the aperture by one level at the same time is the same as photography.

Experience: When shooting high-speed moving objects, you need to consider whether to use it in editing and production: freeze frame, slow motion, etc. If necessary, adjust and increase the shutter speed. The scanning frequency of the picture tube of a TV, especially a computer is high. At this time, the shutter speed (scanning frequency) needs to be adjusted to avoid the phenomenon of rolling flicker of the TV picture taken.

Second, the adjustment of the filter:

Usually cameras have four filters: 3200K, 5600K, 5600K + 1 / 4ND, 5600K + 1 / 16ND.

3200K is used when the color temperature of incandescent, sunrise, and night is 3200K.

5600K is used when the color temperature is 5600K, such as daylight and fluorescent lamps.

5600K + 1 / 4ND can attenuate the aperture, for example: 5600K + 1 / 16ND can attenuate 4 stops.

They are equivalent to the role of light and daylight film in photography.

Experience: Adjust the filter for coarse adjustment of white balance. Adjust the filter according to the color temperature of the shooting scene. Sometimes at a color temperature of 5600K, the aperture is the largest and the slowest, but the amount of light is still insufficient (such as under indoor fluorescent lights). You can also use a 3200K filter to adjust the white balance. The amount of light increases.

At different color temperatures, different color filters can produce different effects. With a 5600K filter, the 3200K scene is shot, and the picture can be warmer. With a 3200K filter, the scene at 5600K can be cold. Such as: reducing the aperture, you can shoot at night under the light of the day.

Third, the black balance:

Adjustments are required when the camera has not been used for a long time or the ambient temperature has changed significantly. Black balance is the basis for accurate white balance. Open the adjustment switch, no matter whether the aperture is manual or automatic, it will be closed, the viewfinder displays 0K, and the black balance adjustment is completed at this time.

Experience: Generally, no adjustment is required.

Fourth, white balance: In order to accurately reproduce the color of the scene, the camera is equipped with: manual adjustment of white balance and automatic tracking of white balance.

Manually adjust the white balance: First select a suitable filter, aim at a white object with a large focal length, and fill at least 90% of the picture (50% can be found in practice). Move the switch to display OK.

Automatic tracking white balance: When the camera moves and the light changes, the camera can automatically track and adjust the white balance in real time. Easy to use.

White balance preset file: Turning on this switch is the preset white balance standard value when the camera leaves the factory.

A and B memory for white balance: The white balance adjusted under two shooting conditions can be stored in A and B. Called at any time.

Experience: Automatic tracking of white balance is fast and convenient, but when used, it is found that there is reddish phenomenon. If in a moving lens, the white balance will also track the color change of the scene at any time, which easily causes the TV screen color to be uneven and unstable.

During shooting, often move back and forth indoors and outdoors, you can develop habits, accumulate experience, good at using A and B white balance storage, to avoid repeated adjustments.

It is found in shooting practice that it is best to use milky white to adjust the white balance (such as rice paper).

Fifth, the directivity of the microphone: Many directional microphones are used in shooting activities. It mainly considers the sound directly in front, and the surrounding sound cannot be easily entered.

Experience: Because it is a directional microphone, the microphone should be facing the sound source. In order to make the picture beautiful, try to prevent the microphone from entering the picture according to the specific situation.

6. Audio level meter: Shows the sound power input to the recorder. Can be adjusted manually and automatically.

Experience: Time, place and other conditions allow manual adjustment, so that no matter how the external sound changes, the sound can be continuously and stably recorded. The sound level cannot exceed 0dB, and the peak value is between -20dB and -30dB.