Color rendition

The Time-Zero film process has an efficient receiving layer consisting of a graft copolymer of 4-vinylpyridine and a vinylhenzyltrimethylammonium salt grafted to hydroxyethylceUulose (81,82). The accuracy of color rendition was improved in the Time-Zero SX-70 film by the use of the xanthene magenta dye-developer (1). 

Because of quite poor color rendition and difficulty in safe disposal of expended lamps, low pressure sodium fixtures are less desirable than high pressure sodium fixtures and are seldom recommended for production facilities. High pressure sodium fixtures are particularly attractive for illuminating large open areas. At locations where power cost is low and where many fixtures are required due to equipment shadowing, mercury vapor fixtures often are preferred because of their lower initial cost, lower replacement lamp cost, and better color rendition. 

PSYCHOPHARMACOLOGICALAGENTS] (Vol20) Average color rendition index... 

Botsolas and I went on a trip to Boston to demonstrate the filter to a number of customers, and he asked me there why we had never made any colored Dylux overlay films. At that time, 3M Co. sold Color-Keys , a series of colored films, which after exposure were immersed in an aqueous solution to remove unexposed areas, thus giving a negative-working colored film. These were overlaid to demonstrate the ultimate color rendition of a printed page. This system was... 

The doped compounds Ce +,Tb + GdMgB50io, and Ce +,Mn + GdMgB50io are used as phosphors in efficient fluorescent lamps having a high color rendition index (see Luminescence). The host is isostructural to the compound... 

Cool white" is a term used by lamp manufacturers and to describe the sensation that people experience in rooms lighted with these fluorescent lamps. These lamps have a CCT of approximately 4100 K. This term was used originally to describe a fluorescent lamp, first produced with a monofluorophosphate phosphor. This lamp was more energy efficient and brighter than the then standard, incandescent lamp and had a good color rendition. It was also the first phosphor used for the mass production of fluorescent lamps. 

As time progressed, the lamp coating composition changed to the present three rare earth phosphors (tri-fluor) of higher efficiency and brightness and superior color rendition than its predecessor. These lamps are not photochemically (spectrally) equivalent. 

Figure 3 shows the SPD of the old (A) and new (B) cool-white lamps. The new triphosphor lamp, based on phosphors developed for television picture tubes is much better at rendering color than the old monofluorophosphor (12). From their SPDs, one could hardly call them equivalent. They do however meet the criteria of color rendition, to "fool the eye", very well. 

Fig. 3. (A) Arrangement of pigment molecules and electron-transfer cofactors in the PS-1 reaction center, viewed along the membrane plane. Numerical values are distances in A. (B) stereo view ofthe same pigment and cofactor molecules as in (A). Both figures adapted from Schubert, Klukas, KrauB, Saenger, Fromme and Witt (A) (1995) Present state of the crystal structure analysis of photosystem I at 4.5 A resolution. In P Mathis (ed) Photosynthesis From Light to Biosphere, II 5. Kluwer (B) (1997) Photosystem I of Synechococcus elongatus at 4 A resolution comprehensive structure analysis. J Mol Biol 272 p 756. Also see Color Plate 10 for a color rendition ofthe electron-density map of (A).

MCCAMY c s, MARCUS H and DAVIDSON J G (1976) A color-rendition chart, Journal of Applied Photographic Engineering, 2, 95. 

Furnace camera technology, while meeting today s needs, continues to evolve and progress as it incorporates the latest advances. Until recently, the state of the art in these cameras was 480 lines of resolution. Recently, 540-line-resolution cameras became available, with better color rendition and more sophisticated electronics. Light volume control, allowing users to adjust the amount of light to see the different areas and depths within the furnace in a bright application, continues to be very critical and is very advanced. 

Yttrium Silicate Y2S105 Ce Eu Blue-green Lamps for high color rendition... 

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. 

Color Rendition (Rendering) Index (CRI) - A measure of light quality. The maximum CRI value of 100 is given to natural daylight and incandescent lighting. The closer a lamp s CRI rating is to 100, the better its ability to show true colors to the human eye. 

Kelvin temperature scale An absolute temperature scale, in which the unit is the Kelvin (K), defined as 1/273.16 of the temperature difference between absolute zero (OK) and the triple point of water. K = °C -h 273. This scale is used to describe the correlated color temperature of light sources and illuminants in color designations and color rendition. Symbol K. See correlated color temperature and Kelvin. Kelvin is used extensively in gas laws and calculation for expansion of gases. Theoretically, all molecular motions cease at OK or absolute zero temperature. Paint pigment, drying oils, polymers, resins, naval stores, cellulosics esters, and ink vehicles, vol 3. American Society for Testing and Material, Conshohocken, PA, 2001. 

Li W, Xie RJ, Zhou T, Liu L, Zhu Y (2014) Synthesis of the phase pure Ba3Si6012N2 Eu2+ green phosphor and its application in high color rendition white LEDs. Dalton Trans 43 6132... 

The prevalent technology of large screen luminescent panels employs plasma excitation of phosphors overlying each display cell. The plasma is formed in low-pressure gas that may be excited by either AC or DC fields. Figure 7.40 depicts a color DC plasma panel. Such devices have been constructed in a variety of sizes and cell structures. Color rendition requires red/green/ blue trios that are excited preferentially or proportionally, as in a color CRT, which triples the number of actual cells (three cells comprise one picture element). 

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