Basic knowledge of lighting technology

I. Visible light

Light is radiant energy that travels as an electromagnetic wave. The wavelength range of electromagnetic wave radiation is very wide, only the wavelength of 380 ~ 760nm in this part of the radiation can cause light vision, called visible light. Light with wavelengths shorter than 380nm is ultraviolet, X-ray, γ-ray; Light longer than 760nm is infrared, radio waves and so on, they do not produce light vision to the human eye, that is, can not see. Therefore, light is an objective existence of energy, and has a close connection with people's subjective feelings.

Two. Color classification

Colors can be divided into two categories: non-colored and colored. Non-color refers to white, light gray, gray to dark gray, until black, called white and black series. Pure white is the ideal object of complete light reflection, its reflectance is 1; Pure black is an ideal non-reflective object with a reflectance of 0. So, the non-colored white and black series represents the change in the reflectance of an object to light. We know that light reflectance is proportional to brightness, and indoor white walls and ceilings can get higher brightness. Color refers to all colors other than white and black series. Color has three characteristics: tone, lightness and saturation, known as the three elements of color.

Hue is the color that is presented. The names of different colors, such as red, green, blue, and so on. It depends on the wavelength of light. Lightness is how bright a color is. Different tonal lightness differs somewhat, although same Tonal because OF the property THAT GETS OBJECT SURFACE AND LIGHT INTENSITY DIFFER ALSO CAN PRODUCE THE DIFFERENCE OF LIGHT AND shade, DEPTH. If BE yellow likewise, CAN have light yellow, medium yellow, dark yellow and so on.

Saturation indicates the depth (intensity) of a color. It can also be said that the purity and vividness of a color. The higher the saturation, the deeper (thicker) the color, and the monochromatic light in visible light is the most saturated color. The more white light is added to a spectral color, the less saturated it becomes. For example, red light is more saturated than pink light because pink light is mixed with white light. Say commonly, in SAME Tonal, when lightness changes, saturation also changes subsequently, but of lightness increase or DECREASE its saturation decreases, only lightness moderate when saturation (purity) ability is the biggest. In the feeling that GIVES a person however, always feel always the color with big lightness LOOKS more bright-coloured.

Three. Primary color and color matching method

Red, green and blue are called the primary colors. These three colors are mixed in different proportions to produce a variety of colors. There are two basic methods of color mixing: additive mixing and subtractive mixing.

Additive mixing is the process by which light rays of different colors, when mixed, add their respective parts of the spectrum together to produce a new way of mixing colors. It shows the color formation relationship of light and color mixture. When the three primary colors of red, green and blue are mixed in equal amount, we can obtain:

Red + green = yellow Green + blue = green

Green + Red = magenta red + green + Blue = white

If different amounts of primary light are mixed, various intermediate colors can be obtained, such as:

More red + less green = orange

More red + less blue = pink

Subtractive blending is the method by which different colors, when mixed, selectively absorb their respective parts of the spectrum from the incident light to produce a synthetic color effect. When any two colors are ADDED together to produce white light, they are called complementary colors. For example, yellow and blue complement each other, green and red complement each other, magenta and green complement each other. Therefore, yellow, cyan and magenta are respectively called reduced blue, reduced red and reduced green, that is to say, the three complementary colors are made by subtracting a corresponding primary color from white light. Therefore, yellow, green, magenta can be called subtractive three primary colors.

Black is produced when three subtractive primary colors, yellow, magenta and cyan, are superimposed. In the process of subtractive color, the density change of the three subtractive primary colors controls the absorption ratio of red, green and blue respectively, so as to obtain a variety of mixed colors, which can achieve the same effect as the additive method.

Color and vision

Colour CAN GIVE A PERSON WARM AND COLD FEELING, DISTANCE FEELING, SIZE FEELING AND WEIGHT FEELING, AND often MAKE THE PERSON TRY TO ASSOCIATE, FORM DIFFERENT PSYCHOLOGICAL EFFECT THEREBY, THESE ARE THE VISUAL HABIT THAT PEOPLE FORMS FOR A LONG TIME.

Colors can usually be divided into three categories: cool colors, warm colors and neutral colors (intermediate colors). Colorific COLD AND WARM ARE ACCORDING TO ALL SORTS OF COLOR TO THE VISUAL RESPONSE THAT CAUSES TO THE PERSON AND THE ASSOCIATION ON PSYCHOLOGY DIVIDE. Red reminds people of the heat of a fire, resulting in a sense of warmth, called warm color. Blue reminds people of cold water and gives people a sense of cold, so it is called cold color. Purple, green is not cold not warm neutral color. Different colors can affect the size of an object's appearance. If a number of different colors of the same size objects together, in the visual sense will produce light white objects larger. Dark black objects are small. In general, white objects look the largest, black objects the smallest, yellow objects the largest, followed by green, red, and blue.

People still can produce sense of near and far to COLORIFIC VISUAL HABIT. Objects of different colors give different visual impressions at the same distance. Warm colors give the impression of moving forward, while cool colors give the impression of moving backward. And the distance that colour gives a person still suffers the influence that background tonal. For example, blue looks closer when you have a white background. Against a black background, red looks closest, followed by orange, yellow, green, blue, and purple. Using this feature can help us create a sense of color three-dimensional, distance illusion effect.

Colorific weight sense also is the visual habit that PEOPLE forms for a long time. It is generally believed that white is the lightest and black the heaviest. Of the three primary colors, green is the lightest, blue the heaviest, and red the middle. A color formed by mixing equal amounts of two primary colors, with light colors appearing light and heavy colors appearing heavy. The sense of weight of color is not only expressed through brightness and purity, but also influenced by the amount of area the color occupies in the picture. Larger colors are heavier and attract more attention than smaller colors.