What does white balance mean in a camera?

The color of the object will change due to the color of the projected light, and the photos taken under different light conditions will have different color temperatures. For example, a photo taken under the illumination of tungsten lamp (light bulb) may be yellow. Generally speaking, CCD can't automatically correct the change of light like human eyes. The following pictures show different images under different colors of light.

The picture uses natural light. After white balance, the image is blue. If white balance is used in light, the color of the picture will return to the primary color state. White balance will immediately adjust the intensity of the red, green and blue colors of the whole image according to the characteristics of the image in the current portrait, and correct the errors caused by external light. Some cameras are not only designed with automatic white balance or specific color temperature white balance function, but also provide manual white balance adjustment and recording.

Balance means that no matter what the ambient light is, the digital camera defaults to white, which means that white can be recognized under colored light and the tones of other colors can be balanced. Color is essentially an explanation of light. What looks white under normal light is not necessarily white under dark light, and white under fluorescent light is also non-white. If we can adjust the white balance for all this, we can correctly restore other colors based on white in the obtained photos. At present, most commercial digital cameras provide white balance adjustment function. As mentioned above, the white balance is closely related to the surrounding light, so the use of the flash will be restricted when the white balance function is started, otherwise the change of ambient light will invalidate the white balance or interfere with the normal white balance. Generally, there are many modes of white balance, which are suitable for different scenes, such as automatic white balance, tungsten wire white balance, fluorescent white balance, indoor white balance and manual adjustment.

Automatic white balance

Automatic white balance is usually the default setting for digital cameras. There is a complex rectangular picture in the camera, and the white balance reference point in the picture can be determined, thus realizing the white balance adjustment. This kind of automatic white balance has high accuracy, but when shooting in light, the effect is poor, and on cloudy days, many automatic white balance systems have poor effects, which may lead to blue. Automatic white balance of tungsten lamp is usually the default setting of digital camera, which hides the skill of flash. There is a complex rectangular diagram in the camera, which can determine the reference point of white balance in the picture, thus realizing white balance adjustment. This kind of automatic white balance has high accuracy, but when shooting in light, the effect is poor, and on cloudy days, many automatic white balance systems have poor effects, which may lead to blue. Fluorescent white balance is suitable for white balance adjustment under fluorescent lamp, because there are many kinds of fluorescence, such as cold white and warm white, so some cameras have more than one kind of fluorescent white balance adjustment. The fluorescent lamps used in different places are different, so the fluorescent settings are different. The photographer must decide which fluorescent lamp to use to achieve the best white balance of the camera. Among all the settings, the fluorescence setting is the most difficult to decide. For example, some offices and schools use various combinations of fluorescent types, and the fluorescent settings here are very difficult to handle. The best way is to try to shoot.

& ampNbsp; Adjust the exposure; Indoor white balance

Indoor white balance, or cloudy or cloudy white balance, is suitable for adjusting the light in the dark to the primary color state. Not all digital cameras have this white balance setting. Generally speaking, the outdoor time-white balance system is in the best state, and these settings are not needed. However, some manufacturers add these special white balance settings to cameras, and the use of these white balances varies from camera to camera. control manually

This white balance has different names in different places, and they describe some white balance settings under ordinary lighting conditions. Generally speaking, users need to point out the reference point of white balance to the camera, that is, which white object is used as the white point in the picture. But the question is what is white. For example, different white papers will have different whites, some may be slightly yellow, flashlights and some white papers may be slightly white, and light will affect our feeling of white. So how to determine the true white? One way to solve this problem is to carry a standard piece of white paper with you and compare the subjects when shooting. This method works very well, so when it is difficult to decide this setting when shooting indoors, you may wish to set the white balance according to the reference white paper. When there is no white paper, let the camera aim at the object that the eyeball thinks is white to adjust.

Photography refers to the process of recording images with some special equipment. Generally, we take photos with mechanical cameras or digital cameras. Sometimes photography is also called photography, that is, the process of exposing the photosensitive medium by using the light reflected by the object.

The word photography in English comes from the Greek word φ ω? Phos (light) and γ ρ α φ ι? Graphis (painting, drawing) or γ ρ α η graph η, together, means "drawing with light". Refers to the process of recording images with some special equipment. Generally, we take pictures with mechanical cameras or digital cameras. Sometimes photography is also called photography, that is, the process of exposing the photosensitive medium by using the light reflected by the object. Someone once said an incisive language:

The photographer's ability is to transform the fleeting ordinary things in daily life into immortal visual images.

Photography, commonly known as photography, is to use a camera to image the negative, and print the negative into a single photo, which is permanently preserved one by one. But the image of the photo is static and silent, just to let people watch its characters and artistic conception, and then understand its meaning.

Today, the earliest existing photos in the world can be traced back to 1827, which was taken by the Frenchman Joseph Nipps.

Concept: principle of photography

Exposure process:

When taking pictures, light enters the cassette through a small hole (more often, a lens group) and forms an image on the medium on the back of the cassette (relative to the incident direction of light). According to the actual light intensity and the photosensitive ability of the medium, the required light time is also different. In the process of illumination, the medium is irradiated by light.

Post production:

After photography is completed, the image information stored in the medium must be read by human eyes again through conversion. The specific method depends on the photosensitive means and medium characteristics. For film cameras, there will be chemical processes such as fixing, developing and enlarging. For a digital camera, a processor is needed to calculate the data and then output it through electronic equipment.

Generally speaking, people take pictures with visible light, and cameras are the most commonly used. Because of different scenes and uses, cameras have many classifications. Generally speaking, a camera must have several basic components to ensure the exposure process, including: photosensitive medium, imaging lens, exposure time control mechanism, film cassette and storage medium.