Lake

They were once thought by early astronomers to be literal lakes. In the 2000s, neon lighting is increasingly yielding to digital vehicle lighting, in which bright LEDs are placed on the car and operated by a computer which can be customized and programmed to display a range of changing patterns and colors, a technology borrowed from Christmas lights. There are dark basaltic plains on the Moon, similar to lunar maria but smaller, that are called lacus (singular lacus, Latin for "lake"). In the 1990s, a popular trend was to customize vehicles with neon lighting, especially underneath the body of a car. Some photographs taken during the Galileo mission appear to show lakes of liquid sulfur on the surface. In the late 1960s and early 1970s, manufacturers would sometimes backlight their logos and or other translucent panelling. Jupiter's small moon Io is volcanically active due to tidal stresses, and as a result sulfur deposits have accumulated on the surface. In addition to lighting for useful purposes, automobiles increasingly feature ornamental lighting.

Under current conditions this water will quickly evaporate or freeze unless insulated in some manner, such as by a coating of volcanic ash. In the image to the right, the top (white portion) of the tail light is the back-up lamp, which when lit, is used to indicate that the vehicle's transmission has been placed in the reverse gear, warning anyone behind the vehicle that it is moving backwards, or about to do so. It is also possible that volcanic activity on Mars will occasionally melt the subsurface ice, forming large lakes. Tail lights are always red and are placed in the rear to quickly alert other drivers about the vehicle's direction of travel. However geologic evidence appears to confirm that ancient lakes once formed on the surface. Headlights are white or yellow lights placed in the front of the vehicle, designed to illuminate the upcoming road and to make the vehicle more visible. At present the surface of the planet Mars is too cold to permit pooling of liquid water on the surface. Vehicles typically include headlights and tail lights.

As of 2005, it is again rapidly losing water, giving rise to the fear that it will be completely dried up by 2010. In the last few years, software has been developed to merge lighting and video by enabling lighting designers to stream video content to their LED fixtures, creating low resolution video walls. Neusiedler See, located in Austria and Hungary, dried up several times for a number years during the past centuries. LED technology is useful for lighting designers because of its low power consumption, low heat generation, instantaneous on/off control, continuity of colour throughout the life of the diode and relatively low cost of manufacture. News sources reported government officials theorized that this strange phenomena may have been caused by a shift on soil underneath the lake which drained water to channels leading to Oka River. Patent disputes of RGB colour mixing ideas are currently slowing development, despite the fact many products are being released that take advantage of red, green, blue, and sometimes white, LEDs to mix colours. On June 3, 2005 in Bolotnikovo, Russia, a lake called White Lake vanished in a short period of time (minutes). LED Technology for theatrical and concert applcations is still in its infancy, but is advancing at an incredible rate.

A prime example of this is Lake Cerknica in Slovenia. White LEDs are about the same efficiency as other fluorescents, while red ones can be up to 90% efficient. Some lakes can also disappear seasonally; they are called Intermittent lakes and are typical of karstic terrain. They are also being increasingly used as Christmas lights. In the very last stages of succession, more trees would grow in, eventually turning the wetland into a forest. Colored LEDs can also be used for accent lighting, even in fake ice cubes for drinks at parties. In lowland river valleys (allowing the river to meander), the presence of peat is explained by the closing of historical oxbow lakes. It appears that for now these will be most useful and cost-effective in smaller applications, starting with nightlights.

Gradually, the lake closes, and young peat may form, forming a fen. These have come about only since the white LEDs they use, and in turn the blue LEDs which they were based on. They become a new habitat for other plants (like peat moss, when conditions are right) and animals, many of which are very rare. They do however last an extremely long time, up to 100,000 hours (compared to around 10,000 for fluorescent and 1,000 for incandescent). A "disappearing" lake (barely noticeable on a human timescale) typically has a water's edge with extensive plant mats. LEDs are a very recent introduction to the market, and they are still extremely expensive for any decent-sized bulb. Turbid lakes, and lakes with much plant-eating fish, tend to disappear slower. HID bulbs are over 60% and up to 80% efficient.

Large water plants (typically reeds) accelerate this closing process significantly because they trap sediment. Like fluorescents, all HID bulbs require a ballast, but they also require a few minutes (or seconds for headlights) to warm up after "igniting". An important difference exists between lowland and highland lakes: lowland lakes are more placid, are less rocky/more sedimentary, have a less sloping bottom, and generally contain more plant life. Modern ones are metal halide, used in everything from headlights to floodlights, and with a more pleasant color balance. A lake may be infilled with deposited sediment, and gradually, the lake becomes a wetland, such as a swamp or marsh. High-intensity discharge lighting first came about with the mercury-vapor streetlights, and later the high-pressure sodium ones with their characteristic orange color. In the daytime, the lake can cool the land beside it with local winds, resulting in a sea breeze; in the night, it can warm it, forming a land breeze. Because the above terms are entirely relative and almost arbitrary, color temperature and/or the color rendering index (CRI) are used as absolute scales of color for fluorescents, and sometimes for other types of lighting.

A lake moderates the surrounding region's temperature and climate because water has a very high specific heat capacity (4186). Compact ones are usually considered warm white, though many have a yellowish cast like an incandescent. It is commonly used to test eutrophication. There is also a very cold daylight white (DW) which is rather unpleasant to most people and therefore rarely used. The depth at which the disk is no longer visible, is the Secchi depth, and is a measure for transparency. In between there is an "enhanced white" (EW), which is more neutral. This is a 20 cm disk with alternating white and black quadrants. Fluorescents most often come in cool white (CW), with some home bulbs being a warm white (WW), which has a pinkish tint.

The light depth or transparency is measured by using a Secchi disk. All last far longer than incandescents, but do have some starting trouble in very cold weather when installed outside. Piscivorous fish eat plant-eating (planktonivorous) fish, thus increasing the number of algae (see aquatic trophic cascade). The compacts can plug into their own fixture, or fit in to a standard screw base for self-ballasted ones. Bottom-dwelling detritivorous fish are responsible for turbid waters, because they stir the mud in search for food. Fluorescents were limited to linear and a few circular ones until the 1980s, when the compact fluorescent was invented. The turbidity is a decisive factor in the transparency of the water. Fluorescent bulbs are about 40% efficient, meaning that for the same amount of light they use 1/4 the power and produce 1/6 the heat of a regular incandescent.

A sediment particle is in suspension if its weight is less than the random turbidity forces acting upon it. People sometimes find them psychologically pleasing over other types of bulbs due to the more natural colour, which lights some skin tones and other artifacts more accurately. Biological particles are algae and detritus. Good halogen bulbs produce a sunshine-like white light, while regular incandescents produce a light between sunlight and candlelight. In very shallow water bodies, iron oxides make water reddish brown. Halogen capsules can be put inside regular bulbs or dichroic reflectors, either for looks or for safety. Decaying plant matter for instance is responsible for a yellow or brown color, while algae result in greenish water. The risk of burns or fire is also greater than other bulbs, leading to their prohibition in some places.

These particles can be sedimentary or biological in origin and are responsible for the color of the water. This means that glass bulbs can explode if broken or brought into contact with cool materials such as water, or if operated with residue such as fingerprints on them. The depth which light can reach in lakes depends on the density and motion of particles. As well as being much smaller and having a hotter filament temperature, this causes halogen bulbs to have a very hot surface. Limnology divides lakes in three zones: littoral zone, which is a sloped area that is close to land; open-water zone, where sunlight is abundant; and deep-water zone, where little sunlight can reach. The bulb capsule is under high pressure instead of a vacuum or low-pressure noble gas. Artificial lakes can also be made deliberately by digging one or by flooding an open-pit mine. Light energy output is about 15% of energy input, instead of 10%, allowing them to produce about 50% more light from the same amount of electrical power.

Some of the world's largest lakes are reservoirs. Halogen bulbs are an improved incandescent. A reservoir (French: réservoir) is an artificial lake created by flooding land behind a dam. Due to their heat output, incandescent bulbs can cause burns or start fires if used improperly. Carbon dioxide is heavier than air, and the released carbon dioxide flows down the river valley. This excess heat is then dumped into the air which, in warm climates, must then be cooled by ventilation or air conditioning, resulting in more energy wastage. Under these circumstances even carbon dioxide is toxic. About 90% of the energy input is wasted as heat.

As the water surfaces, and the pressure drops, a vast amount of gas cab comes out of solution. The incandescent light bulb was the first type of bulb, and is inefficient at converting electricity to light. The amount of gas that can be dissolved in water is pressure related. Cost of replacement lamps is also an important factor in any design. Exceptional events, like earthquakes or landslides, which do cause mixing, that brings up the deep layers, can release a vast cloud of toxic gas. Common characteristics used to evaluate lamp quality include efficiency measured in lumens per watt, typical lamp life measured in hours, and Color Rendering Index on a scale of 0 to 100. The deeper layer becomes oxygen starved, and can become saturated with carbon dioxide, and possibly other gases, like sulfur dioxide, if there is even a trace of volcanic activity. Commonly referred to as 'light bulbs', lamps are the removable/replaceable portion of a luminaire which convert electrical energy to both visible and non-visible electromagnetic energy.

Since the water of deep tropical lakes never reaches the temperature where water reaches its maximum density, there is no process that makes the water mix. These are used for holding acrylic color 'gel', which is available in many hundreds of shades and hues. The reservoir of deep, cold water allows cities to tap that reservoir for deep lake water cooling. All Theatrical Lighting Fixtures should have a steel or metal color or 'gel' frame, which slots into a receiver at the front of the fixture. Deep Temperate lakes can maintain a reservoir of cold water year-round. Floods usually have a halogen tube bulb, backed by a curved symmetric or asymmetric reflector, to give a flat beam to be used for lighting sets or backdrops from above or below. When the density of surface water differs from that of the deeper water there is a marked barrier layer, the thermocline, that prevents mixing. PAR lamps contain a reflector (Parabolic Aluminumized Reflector), filament and lens in an enclosed glass envelope, and have various beam types:.

When the temperature of the water at the surface of a lake reaches the temperature at which water is most dense all the water in the lake can mix, bringing oxygen starved water up from the depths, and bringing oxygen down to decomposing sediments. They basically consist of a tube of steel or aluminum with a rounded removable end, for changing lamps (bulbs). Fresh water is most dense at about 4 degrees Celsius. PARs or PAR cans are among the most simple and widely-used theatrical lighting fixtures. Because of the unusual relationship between water's temperature and its density, the water in lakes in temperate climates mixes twice a year. PCs produce a more focused beam than fresnels, and are suitable for many of the same applications as fresnels and profiles. The are kept liquid because the overlying ice acts as a thermal insulator retaining energy introduced to its underside by friction, water percolating through crevasses, by the pressure from the mass of the ice sheet above or by geothermal heating below. The body of PCs is longer than fresnels.

There are many such lakes, but Lake Vostok in Antarctica is by far the largest. Prism Convex fixtures or 'PCs', are much the same as fresnels, but with a prism convex lens instead of fresnel lens. They can occur under glaciers and ice caps or ice sheets. Large metal 'barndoors' (four in total) are affixed to the front of the lamp on a rotating ring, to cut away unwanted parts of the beam. A subglacial lake is one which is permanently covered by ice. The beam size is adjusted by a screw, which actually moves the bulb of the fixture forwards and backwards within the body of the lamp. A periglacial lake is one in which part of its margin is formed by an ice sheet, ice cap or glacier, the ice having obstructed the natural drainage of the land. These have a pebbled lens with concentric rings, which results in a large hazy circle around the focal point of the lantern.

Such lakes are of little use, and have a poor ecosystem. Used for colour washes, side, front and back-lighting. Lakes typically reach this condition due to human activities, such as heavy use of fertilizers in the lake catchment area. Profiles have one or two convex or plano-convex lenses, which can be adjusted to create a larger or smaller beam, with a hard or soft edge, and have steel shutters placed at the focal point of these lenses, to cut away unwanted portions of the beam. These lakes typically have poor clarity and are subject to algal blooms. Used for front (face) lighting and, with the insertion of a 'gobo' (stainless steel pattern) are used for break-up effects or projecting simple images onto the stage floor or set/backdrop. A hypertrophic lake is a water body that has been highly enriched with nutrients. Although these fixtures are of the 'fixed' variety, they are adjustable to a huge degree.

Eutrophic lakes are enriched with nutrients, resulting in good plant growth and possible algal blooms. Types of fixtures include:. Mesotropic lakes have good clarity and an average level of nutrients. Connectors are fuseless, as the fuse for the fixture is provided at the dimmer end of the circuit. Nutrient poor lakes are said to be oligotrophic, and are generally clear, having a low concentration of plant life. A short cable is normally hardwired or connected to the body of the light and has an electrical connector on the end. Lakes can be categorized on the basis of their richness of nutrients, which typically effects plant growth. Power for the fixtures is provided by dimmers which receive control signal, either digitally multiplexed (DMX) or analog + / − 12v from the main lighting desk or console, where all of the lights used in a production are controlled.

As climate conditions and human water requirements vary, these will create fluctuations in the lake level. Conventional Fixtures are stationary or 'fixed' and normally controlled by a power cable, allowing the fixture to output a beam of light with a brightness of 0 to 100 percent. Output sources are evaporation from the lake; surface and groundwater flows, and any extraction of lake water by humans. Generally, standard sound XLR cabling is not suitable for lighting, because the gauge of the wire is too small. The significant input sources are precipitation onto the lake; runoff carried by streams and channels from the lake's catchment area; groundwater channels and aquifers, and man-made sources from outside the catchment area. The protocol runs on standard three pin XLR cable, although, some older theatres still use five pin DMX cabling. The change in level of a lake is controlled by the difference between the sources of inflow and outflow, compared to the total volume of the lake. In the United States, automated lighting fixtures are normally controlled by the United States Institute of Theatre Technology Digital Multiplex - 512 Channel Standard Protocol, or simply DMX-512.

Some lakes come into existence as a result of sinkhole activity. Automated lighting fixtures use digital electronics to adjust the color, position, beam angle, brightness, and other special effects. The Crater Lake in Oregon is a lake located within the caldera of an extinct volcano. Conventional lighting consists of stationary lights that can only be moved manually, by means of adjusting, or focusing the fixture with a yoke. Some lakes, like Lake Baikal and Lake Tanganyika are volcanic in origin, and lie on geological fault lines. Concert and theatre lighting use special types of fixtures. The pressure from ice and the internal chemical composition means that if the lake were drilled into, it may result in a fissure and spraying in the same manner as a shaken can of soda. It is usually a floor lamp but may be wall-mounted like a sconce.

Lake Vostok is an under-ice lake in Antarctica, possibly the largest in the world. A torchiere (tour-she-AIR or tour-SHARE) is an uplight usually intended for general lighting. This gap now forms the main passage for the river and the ends of the bend become silted up. A sconce is a wall-mounted fixture, particularly one that shines up and sometimes down as well. Eventually a horseshoe bend is formed and the river cuts through the narrow neck. Nearly any material can be used, so long as it can tolerate the heat and is in keeping with safety codes. The slow-moving river forms a sinuous shape as the outer side of bends is torn away more rapidly than the inner side. Some are very plain and functional, while some are pieces of art in themselves.

Small, crescent-shaped lakes called oxbow lakes can form in river valleys as the result of meandering. Lighting fixtures come in a wide variety of styles for various functions. Examples of salt lakes include the Great Salt Lake, the Caspian Sea and the Dead Sea. Underwater accent lighting is also used for koi ponds and the like. Saline lakes can form where there is no natural outlet or the water evaporates rapidly, and the drainage surface of the water table has a higher than normal salt content. This would probably fall under accent lighting, though in a dark nightclub it could be considered general lighting. When the ice retreated, the result was an immense flood that created the Dry Falls at Sun Lakes, Washington. Other forms include neon, which is not usually intended to illuminate anything else, but to actually be the artwork in itself.

An example of the latter occurred during the last ice age in the state of Washington, when a huge lake formed behind a glacial flow. This uses diffuser panels hung like a suspended ceiling below fluorescent lights, and is considered general lighting. Lakes can also form by means of landslides or by glacial blockages. The illuminated ceiling was once popular in the 1960s and 1970s but fell out of favor after the 1980s. Such lakes are common in Scandinavia, Siberia and Canada. Magnifier lamps are also task lighting. The advance and retreat of glaciers can scrape depressions in the surface where lakes accumulate. The standard lamp and shade that sits on a table is general lighting, while the desk lamp is considered task lighting.

A recent tectonic uplift of a mountain range can create bowl-shaped depressions that accumulate water and form lakes. The lamp is probably the most common fixture, found in every home and many offices. There are a number of natural processes that can form lakes. A modified version of this is cable lighting, where lights are hung from or clipped to bare metal cables under tension. Most lakes are young, as the natural results of erosion will tend to wear away one of the basin sides containing the lake. There are traditional spots and floods, as well as other small hanging fixtures. . A master transformer feeds all of the fixtures on the track or rod with 12 or 24 volts, instead of each having its own.

Over 60% of the world's lakes are in Canada; this is because of the deranged drainage system that dominates the country. It has regained some popularity recently in low-voltage tracks, which often look nothing like their predecessors because they do not have the safety issues that line-voltage systems have, and are therefore less bulky and more ornamental in themselves. The Great Lakes of North America originated in the ice age. Track lighting, invented by Lightolier, was popular at one point because it was much easier to install then recessed lighting, and individual fixtures are decorative and can be easily aimed at a wall. Finland is known as The Land of the Thousand Lakes (actually there are 187,888 lakes in Finland, of which 60,000 are large) and Minnesota is known as The Land of Ten Thousand Lakes. True can lights are uplights, sitting on the floor in a can-like fixture, or mounted on a spike or even in the ground for plants or outdoors. Many lakes are artificial and are constructed for hydro-electric power supply, recreation (swimming, wind surfing,...), water supply, etc. Either type can be incandescent, fluorescent, HID or LED, though only incandescents or LEDs make narrow-enough spots.

The term lake is also used to describe a feature such as Lake Eyre, which is dry most of the time but becomes filled under seasonal conditions of heavy rainfall. They may also have their own reflector built-in to the fixture, so that they can take regular and less-expensive bulbs. Large lakes are sometimes referred to as "inland seas" and small seas are sometimes referred to as lakes. These downlights use narrow spotlights or "spots", or wider-angle floodlights or "floods", which are both bulbs with their own reflectors. The majority of lakes are fresh water, and most lie in the Northern Hemisphere at higher latitudes. Recessed lighting (often called pot lights in Canada and can lights in the U.S.) is popular, with fixtures mounted above the ceiling so as to appear flush with it. A lake is a body of water surrounded by land. The effect depends heavily on the exact type of lighting used.

Before the current city boundaries came into effect in 2001, this status was held by Lake Ramsey, also in Sudbury. Soffit lighting can be general or a decorative wall-wash, sometimes used to bring out texture (like stucco or plaster) on a wall, though this may also show its defects as well. The largest lake located completely within the boundaries of a single city is Lake Wanapitei in the city of Greater Sudbury, Ontario, Canada. It is a form of backlighting. Lake Titicaca is the largest freshwater lake in South America. This is often done with fluorescent lighting or rope light, or occasionally with neon lighting. It however lies at sea level with a relatively wide opening to sea, so it is better described as a bay. Particular forms include alcove lighting, which like most other uplighting is indirect.

Lake Maracaibo can be considered as the largest lake in South America. Backlighting either around or through an object is mainly for accent. It is a part of the Great Lakes of Africa. Lighting from the side is the less common, as it tends to produce glare near eye level. Lake Victoria is the largest lake in Africa. Lighting from the front is also quite common, but tends to make the subject look flat as its casts almost no shadows. The largest freshwater lake in Europe is Lake Ladoga, followed by Lake Onega, both in north-western Russia. It can also be used for dramatic effect, such as creating interesting shadows by shining through houseplant leaves or across coarse textures like brick or stone.

Lake Toba on the island of Sumatra is located in what is probably the largest resurgent caldera on Earth. Uplighting is less common, often used to bounce indirect light off of the ceiling and back down, though this is less efficient than direct lighting. The largest lake located on an island is Nettilling Lake on Baffin Island. This tends to be the most efficient method, used in both offices and homes. The largest freshwater-lake island is Manitoulin Island on Lake Huron, with a surface area of 2,766 square km. Downlighting is most common, with fixtures on the ceiling casting light downward. It is also one of the lakes with highest salt concentration. Outdoors, general lighting for a parking lot may be as low as 10-20 lux (1-2 footcandles) since pedestrians and motorists already used to the dark will need little light for crossing the area.

The world's lowest lake is the Dead Sea, currently (2005) 418 m (1,371 ft.) below sea level. Indoors, this would be a basic lamp on a table or floor, or a fixture on the ceiling. The world's highest lake is Lhagba Pool in Tibet at 6,368 m. General lighting fills in between the two and is intended for general illumination of an area. It is also the second largest lake in South America. Accent lighting is mainly decorative, intended to highlight pictures, plants, or other elements of interior design or landscaping. The highest navigable lake is lake Titicaca, at 3821 m above sea level. For example, reading poor-quality reproductions may require task lighting levels up to 1500 lux (150 footcandles), and some inspection tasks or surgical procedures require even higher levels.

The world's oldest lake is Lake Baikal, followed by Lake Tanganyika (Tanzania). Task lighting is mainly functional and is usually the most concentrated, for purposes such as reading or inspection of materials. The deepest lake is Lake Baikal in Siberia, with a bottom at 1,637m (5,371 ft.) and is the world's largest freshwater lake by volume. Lighting is classified by its intended use as general, localized, or task lighting, depending largely on the distribution of the light produced by the fixture. All these are part of the Great Lakes of North America. Since the exact orientation of printed material may not be closed controlled, a visual comfort probability can be calculated for a given set of lighting fixtures. km, sometimes designated Lake Michigan-Huron. Proper selection of fixtures is complicated by the requirement to minimize the veiling reflections off of printed material.

However, Lake Huron and Lake Michigan form a single hydrological system with surface area 117,350 sq. Empirically-established depreciation factors are listed in lighting design handbooks. km. Practical lighting design must take into account the gradual decrease in light levels from each lamp owing to lamp aging, lamp burnout, and dirt accumulation on fixture and lamp surfaces. The largest freshwater lake, and second largest lake altogether, is Lake Superior with a surface area of 82,414 sq. Hand calculations might only be required at a few points, but computer calculations allow a better estimate of the uniformity and lighting level. km., it has a surface area greater than the next six largest lakes combined. Again the tabulated light levels (in lux or foot-candles) can be presented as contour lines of constant lighting value, overlaid on the project plan drawing.

With a surface area of 394,299 sq. Where multiple lamps are used to illuminate the same area, each one's contribution is summed. The largest lake in the world by surface area is the Caspian Sea. Each region is extended to the surface which is to be lit and the area calculated, giving the light power per unit of area. The total lighting power of a lamp is divided into small solid angular regions. Modelling of outdoor flood lighting usually proceeds directly from photometric data.

Simplified photometric values are usually given by fixture manufacturers for use in this method. This method uses the reflectance coefficients of room surfaces to model the contribution to useful illumination at the working level of the room due to light reflected from the walls and the ceiling. The Zonal Cavity Method is used as a basis for both hand, tabulated, and computer calculations. More advanced programs can include the effect of light from windows or skylights, allowing further optimization of the operating cost of the lighting installation.

The computer program will then produce a set of contour charts overlaid on the project floor plan, showing the light level to be expected at the working height. Each fixture has its location entered, and the reflectance of walls, ceiling, and floors can be entered. For larger projects or those with irregular floor plans, lighting design software can be used. Based on the positions and mounting heights of the fixtures, and their photometric characteristics, the proposed lighting layout can be checked for uniformity and quantity of illumination.

For very simple layouts in common configurations, tables and simple hand calculations can be used. This certification process is the only national examination in the lighting industry and is open not only to designers, but to lighting equipment manufacturers, electric utility employees, etc. Individuals who pass this exam become ‘Lighting Certified’ and may append the abbreviation LC to their name. The National Council on Qualifications for the Lighting Professions (NCQLP) offers the Lighting Certification Examination which tests rudimentary lighting design principles.

Those fully independent designers who meet the requirements for professional membership in the association typically append the abbreviation IALD to their name. The International Association of Lighting Designers (IALD) is an organization which focuses on the advancement of lighting design education and the recognition of independent professional lighting designers. This data is typically expressed in standardized form defined by the IESNA. Manufacturers of lighting equipment publish photometric data for their products, which defines the distribution of light released by a specific luminaire.

The Illuminating Engineering Society of North America (IESNA), in conjunction with organizations like ANSI and ASHRAE, publishes guidelines, standards, and handbooks that allow categorization of the illumination needs of different built environments. Lighting design requires the consideration of several design factors:. These electrical lighting systems should also consider the impacts of, and ideally be integrated with, daylighting systems. Therefore, it is important that the sciences of light production and luminaire photometrics are balanced with the artistic application of light as a medium in our built environment.

Other buildings, like casinos and theatres, are primarily concerned with enhancing the appearance and emotional impact of architecture through lighting systems. Some buildings, like warehouses and office buildings, are primarily concerned with saving money through the energy efficiency of the lighting system. Some buildings, like surgical centers and sports facilities, are primarily concerned with providing the appropriate amount of light for the associated task. Proper comprehensive lighting design requires consideration of the amount of functional light provided, the energy consumed, as well as the aesthetic impact supplied by the lighting system.

Lighting design as it applies to the built environment, also known as 'architectural lighting design', is both a science and an art. . In major cities, light pollution is of growing concern. Smaller or rural roads may not be lit.

These are a form of street furniture. In cities, streets are often lighted at night, usually by streetlights (also known as lamp-posts). Likewise, lighting can also be an important part of landscaping. Indoor lighting is a form of furnishing, and a critical part of interior design.

Modern portable lighting is typically a flashlight (also called a torch) running on batteries. Modern freestanding lamps typically have a base which holds up a light bulb which is covered by a lampshade. Indoor lighting is provided by light sources, today usually electric lights, but previously by gas, candles or oil lamps. "Natural" indoor lighting is light from the sun and the sky coming through the windows.

Lighting refers to the devices or techniques used for illumination, usually referring to electrical light sources such as lamps or flashlights. Very wide Flood. Wide Flood (W or CP62). Medium Flood (M).

Narrow Spot (NS or CP61). Very Narrow Spot (VNS or CP60). Flood (used primarily for lighting backdrops). PAR (exchangeable bulbs create varying beam angles/effects).

Prism Convex (variable beam angle). Fresnel (variable beam angle). Profile spot (various beam angles). electrical codes and building codes.

operating schedule of the building. maintenance capabilities. dirt and dust generation/accumulation. surface characteristics (reflectance, specularity).

physical size of the environment. aesthetic architectural impact. initial and continued operational costs. occupants of the environment.

tasks occurring in the environment.