company news about Basic Knowledge Of Auto Paint Color Center

1 Light

a. The composition of light. Light is an electromagnetic radiation and an electromagnetic wave. The light we usually see is called visible light, and its wavelength range is between 400 and 700nm. In addition to this range, there are ultraviolet rays and infrared rays .

b. Composition of white light Clean white light is composed of six colors of red, orange, yellow, green, blue, and purple. All these colors form a spectrum.

c. Formation of the color of the object The surface of the object contains pigments. The pigments selectively reflect some light while also absorbing other light. The pigment determines the color of the object. The color of the non-transparent body is reflected by the color of the light reflected by it. For example, when white light is irradiated on an object containing red pigment, it can only reflect red light, so red is observed. If there are both red and yellow pigments, orange is observed. The transparent body is reflected by the color of the light transmitted through it. White paint can reflect all light, and black paint cannot reflect any light.

d. Types of light sources There are natural light sources and artificial light sources. The spectral curve of sunlight is higher at the blue end of the spectrum, so it is said that sunlight is bluish in nature. The wavelength produced by an incandescent lamp tends to peak at the red end of the spectrum, which belongs to warmer light. The fluorescent lamp curve emits more energy in the blue part of visible light, which belongs to colder light. After sunrise and 3h before sunset is a good time to observe and analyze colors.

2. Object

Objects can be divided into two categories: luminous bodies and non-luminous bodies. When a light source illuminates a non-luminous object, the object has three reactions of reflection, transmission and absorption to the light irradiated on its surface, thus forming a sense of color. If the object contains pigment, the pigment will selectively reflect part of the light and absorb other light. The reflected light determines the color of the object.

3. Observer

The visual characteristics of the observer's eyes are the physiological basis for color perception. A person with normal color perception perceives the visible spectrum as a series of consecutive colors in the order: dark red, bright red, orange, yellow, bright green, green, blue, and dark purple. People's perception of color is subjective, and people with color vision defects cannot distinguish colors correctly, so they are not suitable for color matching. Because women have a stronger sense of color than men, the probability of suffering from color blindness is low, and they have the characteristics of being careful. Therefore, most of the staff engaged in color matching and color measurement are women.

4. The interaction between the three elements

Color is a combination of object reflection, light source and observer. If any of these three factors change, the resulting color will change accordingly.

5. Light source discoloration

Discoloration of light source Two objects show the same color under a certain light source, but when observed under different light sources, there will be obvious color difference. The fundamental reason is that the pigment contained in the object is different, and the intensity of various colored lights in different light sources is also different. Therefore, it is necessary to check the color matching under the light source conditions that may cause the light source to change color. This phenomenon occurs in color mixing, which may be due to the different pigments used in the repair paint and the original paint formula, resulting in different colors under different light sources, which requires the addition of toner in the formula to solve.

6. Standard light source and visual perception

Standard light source: the light source agreed by the color worker. "Standard Illuminant A" represents the light of a complete radiator with a temperature of about 2856K; "Standard Illuminant B" represents direct sunlight with a correlated color temperature of about 4874K, which is equivalent to noon sunlight; "Standard Illuminant C" represents a correlated color temperature of about 6774K average daylight; "standard illuminant D65" represents the daylight phase with a correlated color temperature of about 6504K.

Visual sense colorimetry is to arrange the color of the sample and the color of the sample side by side, and observe whether they are the same with the naked eye. The visual comparison of the lighting is to use natural light from 3h after sunrise to 3h before sunset, avoid direct sunlight, and use the light entering from the northern window. The line of sight and the light form an angle of 45 °, and one of the line of sight and the light is perpendicular to the sample. The result of colorimetry, if the two color samples are completely isochromatic when viewed under any light source, it is called the same color and the same spectrum; if the two samples are isochromatic when viewed under a certain light source, and under another light source Observation is unequal, this phenomenon is called metamerism.

7. The nature of color

The nature of color is hue, lightness, and chroma. It is also called the three spaces of color or the three attributes of color. To describe a color completely and accurately, it is necessary to include these three aspects.

a. Hue Hue (also called hue) is the difference between colors, and is the color appearance of monochromatic light of a certain wavelength. Hue is a property (attribute) of color, which allows us to describe objects as red, orange, yellow, green, blue, and purple. The basic hues in the color system are red, yellow, and blue. They are also called "primary colors", and almost all colors can be mixed with them. The orange, green, and purple are the primary colors of red, yellow, and blue, which are prepared in twos according to the ratio of 1: 1, and are called "three-color". These six colors are also called the six basic colors of color. From the perspective of colored light, the hue changes with the change of wavelength. Fuchsia, red, orange and so on all indicate that each specific hue in the middle of the red class, the difference between these three reds is a hue difference. The same hue may be darker or lighter.