Before answering this question, we must first know what color temperature and brightness are? Color temperature (color temperature) is a scale that indicates the color of a light source, and the unit is K (Kelvin). Color temperature has important applications in photography, videography, publishing and other fields.
The color temperature of a light source is determined by comparing its color with a theoretical thermal black body radiator. The Kelvin temperature when the thermal black body radiator matches the color of the light source is the color temperature of the light source, which is directly related to Planck’s black body radiation law.
Luminous flux refers to the radiant power that the human eye can perceive, which is equal to the product of the radiant energy of a certain band per unit time and the relative visibility of the band. Since the relative visibility of the human eye to light of different wavelengths is different, when the radiant power of light of different wavelengths is equal, the luminous flux is not equal, which we usually call brightness. Therefore, our SMD LED and SMD LED lamps produce light color K by exciting phosphors with 460nm blue light. It can be adjusted from 1000-100000K according to needs. Commonly used are warm light 2000K-3500K, natural white 4000K-5500K, pure white light 5500-6500K, and cold white light 6500.
Because the relative visibility of different wavelengths of light is different, when the radiation power of light of different wavelengths is equal, its luminous flux is not equal, that is to say, the color temperature and brightness of the same product and the same material are different. For example, a 2835 chip is the brightest at 28-30lm between 5500-6500K, but at 3000K it is 26lm-28LM, and above 6500 it can only reach 26-28LM. The higher the color temperature, the lower the brightness. In addition to color temperature, there is also color rendering, which has a great impact on brightness. Similarly, between 5500-6500K, 28-30lm is the brightest, but if it is made into a color rendering index of 80, it becomes 26-28lm, and the material is the same as that of 30.