Color Rendering Properties

These lamps show moderately good color rendering properties, the very broad spectrum being one of their main utilities. For instance, high-pressure Xe lamps or deuterium lamps are commonly used in optical spectroscopy techniques. 

The intermediate color-rendering properties of most fluorescent light sources are closer to the best than to the worst. Mercury vapor and high-pressure sodium sources, widely used for street lighting, have poor color-rendering properties that fall between those of fluorescent and low-pressure sodium illumination. 

Once the job is completed, the UniChem GUI can be used to visualize results. It can be used to visualize common three-dimensional properties, such as electron density, orbital densities, electrostatic potentials, and spin density. It supports both the visualization of three-dimensional surfaces and colorized or contoured two-dimensional planes. There is a lot of control over colors, rendering quality, and the like. The final image can be printed or saved in several file formats. 

Apart from the color point, there is another important lamp characteristic, viz. the color rendition. This property depends on the spectral enei distribution of the emitted light. It is characterized by comparing the color points of a set of test colors under illumination with the lamp to be tested and with a black body radiator. The color rendering index (CRl) equals 100 if the color points are the same under illumination with both sources. Under illumination with a lamp with low CRI, an object does not appear natural to the human eye. 

Qian HJ, Zhang JY, Yin LQ (2013) Crystal structure and optical properties of white light Emitting Y2W06 Sm phosphor with excellent color rendering. RSC Adv 3 9029... 

When it consists of only silica and water, flint is basically colorless. Impurities within the stone, however, render colored varieties. Thus, much flint is tan, beige, or jet black with a brown homy appearance (the latter color is caused mainly by iron impurities), but there are also gray, pink, and even red varieties. If dark flint is heated to temperatures above 450°C, the outer layer changes to white. Flint that underwent such a heating process is known as burned or calcinated flint, a misnomer probably used because the white surface appears to have changed into lime (Luedtke 1992 Sieveking and Bart 1986). Burned flint is easier to work than is the natural mineral, a property... 

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