Color and Light We tend to think of objects as having fixed colors—an apple, for example, is red. In reality, an object’s appearance results from the way it reflects the particular light that is falling on it. Under white light, the apple appears red because it tends to reflect light in the red portion of the spectrum and absorb light of other wavelengths. If a filter is used to remove red from the light source, the apple reflects very little light and appears black. The fact that the color makeup of light can change, means that shifts can occur in the color appearance of objects illuminated by it. Within limits, the brain compensates for these changes in color appearance and we see things as we expect them to appear. But the changes are there nonetheless and can affect the way people respond to objects and environments. All Light Is Not the SameThere is a great variety in the color makeup of light that appears white. Direct sunlight at noontime is an almost perfectly balanced light source—it contains all colors in nearly equal quantities.

But daylight does experience color shifts. The color appearance of objects changes dramatically in early morning or in the shade. Electric light sources can also exhibit variations in color makeup. Incandescent lamps tend to produce more red and yellow light than green and blue, and appear to be “warm” in color. Because of the way incandescent light is produced, little can be done to manipulate its color characteristics. With fluorescent and high intensity discharge lighting, this latest technology makes it possible to manipulate the color makeup of a given light source. White Light and Bright ColorsGenerally speaking, whiter light (comprised of equal amounts of all colors) makes colors appear more natural and vibrant. However, some portions of the spectrum are more important to a light’s color makeup than others. Red, blue and green—the primary colors of light—can be combined to create almost any other color. This suggests that a light source containing balanced quantities of red, blue and green light can provide excellent color appearance even if this light source is deficient in other colors in the spectrum.

Full-spectrum light is light that covers the electromagnetic spectrum from infrared to near-ultraviolet, or all wavelengths that are useful to plant or animal life; in particular, sunlight is considered full spectrum, even though the solar spectral distribution reaching Earth changes with time of day, latitude, and atmospheric conditions. "Full-spectrum" is not a technical term when applied to an electrical light bulb but rather a marketing term implying that the product emulates natural light. Products marketed as "full-spectrum" may produce light throughout the entire spectrum, but actually do not produce an even spectral distribution, and may not even differ substantially from lights not marketed as "full-spectrum". Color temperature and Color Rendering Index (CRI) are the standards for measuring light. There is no technical definition of "full-spectrum" so it cannot be measured. To compare "full-spectrum" sources requires direct comparison of spectral distributions.

A cube of carbon "C" will radiate light of varying spectral power distribution (SPD) as it is heated. Moen Bathroom Faucet Hard To TurnAt 0 K, it is pure black, while at about 5,000 K to 5,500 K, it appears similar to noon daylight.Asics Shoes For Heel Spurs Ideally, during the day, the art studio should be lit with northern sunlight (in the northern hemisphere), because it is considered more neutral and diffused than the direct, "yellowish" quality of southern sunlight.Coldwater Catfish For Sale[] Since many artists' studios don't have north-facing windows, full-spectrum lamps are sometimes used to approximate such light. Full-spectrum fluorescent lamps are also used by color scientists, color matchers in paint stores and quilters and others working with fabrics or yarn when working under inadequate lighting conditions to assist in achieving the correct hues as they will later appear in daylight or under gallery lighting.

Full spectrum lighting is used both for tropical and marine fish as well as many other water pets. The use of full spectrum lighting assists aquarium plants to grow and aids in the health of the fish and the tank as a whole. Gardening under lights keeps plants blooming almost year-round, for a wintertime harvest. Grow lights are specifically intended to support plant growth, although with varying degrees of success and energy efficiency. Some plants grow better when given more of a certain color light, due to the mechanism of photosynthesis. Specifically more blue wavelengths enhance vegetative growth and development, while the addition of increasing amounts of red light enhances budding, flowering and fruiting. In recent years, full-spectrum lighting has been used in the treatment of seasonal affective disorder (SAD) through the use of "light boxes" that mimic natural sunlight, which may not be available in some areas during the winter months. Light is an environmental stimulus for regulating circadian cycles.

Lightbox therapy, otherwise known as phototherapy, is a recognized modality for depression (such as SAD). It is also the primary treatment for circadian rhythm sleep disorders. Depending on the quality of the light, it is estimated that 10,000 lux is needed for effective treatment. Not all light boxes are the same, and some produce only blue or green light. The non-profit Lighting Research Center, a group of utility companies, experts and government agencies, established the National Lighting Product Information Program (NLPIP) in the USA to provide objective information about the effectiveness of different lighting systems. According to the NLPIP, full-spectrum light does not provide any improved benefits over similar light systems. A Cornell University study reached mixed conclusions on the use of full-spectrum lighting in restaurants to promote sales. The National Research Council of Canada Institute for Research in Construction, a Canadian government research and development agency, has published several scientific articles about full-spectrum lighting, collected on their web page.