Lighting is the usage of light to achieve an aesthetic effect and that can be achieved by using both artificial light like lamps and light fixtures as well as natural illumination by capturing daylight

Low-intensity lighting and haze in a concert hall allows laser effects to be visible

Light fixtures

Day lighting using (windows, skylights or light shelves) can be the main source of light in some buildings for saving energy consumption.

Skylight

Light shelves

Light shelves

Indoor lighting is usually accomplished using light fixtures, and is a key part of interior design. Lighting can also be an intrinsic component of landscape projects.

Light fixtures

Lighting fixtures come in a wide variety of styles for various functions. The most important functions are as a holder for the light source, to provide directed light and to avoid visual glare. Some are very plain and functional, while some are pieces of art in themselves. Nearly any material can be used, so long as it can tolerate the excess heat and is in keeping with safety codes.

Color temperature for white light sources also affects their use for certain applications. The color temperature of a white light source is the temperature in Kelvin of a theoretical black body emitter that most closely matches the spectral characteristics of the lamp. An incandescent bulb has a color temperature around 2800 to 3000 Kelvin; daylight is around 6400 Kelvin. Lower color temperature lamps have relatively more energy in the yellow and red part of the visible spectrum, while high color temperatures correspond to lamps with more of a blue-white appearance. For critical inspection or color matching tasks, or for retail displays of food and clothing, the color temperature of the lamps will be selected for the best overall lighting effect.

Color temperature of a heated metal

The effect of increasing heat on light color

Types of lighting

Task lighting

Task lighting is mainly functional and is usually the most concentrated, for purposes such as reading or inspection of materials. For example, reading poor-quality reproductions may require task lighting levels up to 1500 lux (150 foot-candles), and some inspection tasks or surgical procedures require even higher levels

A lux meter for measuring illuminances in work places.

Accent lighting

Accent lighting is mainly decorative, intended to highlight pictures, plants, or other elements of interior design or landscaping.

General lightingGeneral lighting (sometimes referred to as ambient light) fills in between the two and is intended for general illumination of an area. Indoors, this would be a basic lamp on a table or floor, or a fixture on the ceiling. Outdoors, general lighting for a parking lot may be as low as 10-20 lux (1-2 foot-candles) since pedestrians and motorists already used to the dark will need little light for crossing the area.

Methods of lighting

• Down lighting• Up lighting• Front lighting

Down lighting

Down lighting is most common, with fixtures on or recessed in the ceiling casting light downward. This tends to be the most used method, used in both offices and homes. Although it is easy to design it has dramatic problems with glare and excess energy consumption due to large number of fittings. The introduction of LED lighting has greatly improved this by approx. 90% when compared to a halogen down light or spotlight. LED lamps or bulbs are now available to retro fit in place of high energy consumption lamps

Up lighting

Uplighting is less common, often used to bounce indirect light off the ceiling and back down. It is commonly used in lighting applications that require minimal glare and uniform general illuminance levels. Up lighting (indirect) uses a diffuse surface to reflect light in a space and can minimize disabling glare on computer displays and other dark glossy surfaces. It gives a more uniform presentation of the light output in operation. However indirect lighting is completely reliant upon the reflectance value of the surface. While indirect lighting can create a diffused and shadow free light effect it can be regarded as an uneconomical lighting principle.

Front lighting

Front lighting is also quite common, but tends to make the subject look flat as its casts almost no visible shadows. Lighting from the side is the less common, as it tends to produce glare near eye level. Backlighting either around or through an object is mainly for accent

Architectural lighting design

Architectural lighting design is a field within architecture, interior design and electrical engineering that is concerned with the design of lighting systems, including natural light, electric light, or both, to serve human needs.The design process takes account of:

• the kind of human activity for which lighting is to be provided.• the amount of light required.• the color of the light as it may affect the views of particular objects and the

environment as a whole.• the distribution of light within the space to be lighted, whether indoor or outdoor.• the effect of the lightened system itself on the user.

Lighting tips for each room

Living roomLight three of the four corners, focusing one of those lights on an object (art, a plant, a striking chair). Use a combination of table lamps and floor lamps, some with a downward glow and some that shine upward. If you have an overhead fixture, put it on a dimmer and always avoid direct visual glare.

Dining room

Make the table the brightest spot in the room. Use a chandelier or a pendant above the table, limiting the total wattage to 100. Elsewhere in the room, indirect lighting is best—it’s relaxing and flattering. Give the space a subtle glow with a pair of small table lamps on a sideboard or matching sconces on the wall above. Battery-powered votives inside a glass-front china cabinet can be a nice touch.

KitchenFocus on overhead lighting (on a dimmer that you can crank up when cooking), and add lower sources to illuminate work surfaces. Use pendants, under-cabinet lights, or a sturdy table lamp (kept away from the sink).

BedroomAim for a cozy, insular atmosphere: Place reading lamps or sconces by the bed—but not pointed directly at it. If you have recessed or track fixtures, angle them away from the bed, toward the dressing area. On a low table, include a small, intimate lamp with a tinted low-wattage bulb to mimic candlelight.

BathroomThe best choice for applying makeup is sidelights, such as a pair of sconces flanking the mirror. An overhead light helps fill in any shadows on your face and also fully illuminates the room (important when cleaning). In a large space, you might also want a light directly over the shower.

Flush-mount Fixtures like these hug the ceiling. In a bathroom or a kitchen, their bright, whole-room illumination is useful; elsewhere they can be harsh. Calm one down by swapping in low-wattage bulbs, aiming for a total wattage of about 60.

Kitchen Pendants

They should clear the head of the tallest family member and not obstruct views—figure 36 to 48 inches from the top of the counter. Start the row of lights 12 to 15 inches from either end of the island or table, and space them evenly within that span.

Go for a fixture one-half to three-quarters the width of the table; anything larger will cast shadows on faces. Hang the light 36 to 48 inches above the table. Choose the lower number for more intimacy, the higher one if you want to stand when toasting.

Reading lightUse a 40- to 60-watt bulb. To prevent shadows, the lamp should be between your head and the page. A lamp with an opaque shade, like a metal reading lamp, cuts glare.

1: Silver BowlA metallic finish on the top half of the bulb softens the light. A great solution for overheads with exposed bulbs, especially if there isn’t a dimmer. (Halco clear silver-bowl globe, $3, 1000bulbs.com.)

2: Soft PinkEmits a gorgeous, rosy glow. Perfect for mood lighting in the living room, the dining room, or a bedroom. Once you switch, you’ll never go back. (Sylvania soft pink bulbs, $5.50 for two, hardwarestore.com.)

3: Round CandelabraTry these in a modern chandelier. Or, for a surprise, swap them in for the flame-shaped bulbs in a traditional chandelier. (GE crystal-clear globe lightbulbs, $3, amazon.com.)

4: EdisonInspired by Thomas Edison’s original design, it has a visible filament and a rustic glow. Pricey and low-wattage, it’s worthwhile only in lamps where the bulb is exposed. (Triple-loop bulb, $25, rejuvenation.com.)