Types of Light Sources

After you've chosen your lighting fixtures, the next step is to select an appropriate light source (light bulb/lamp) for each one. The performance of any light fixture depends very much on the light source (light bulb) used. Different sources produce different effects. Light is measured in terms of:

Wattage: the amount of electricity consumed by a light bulb

Lumens: the amount of light produced by a light bulb

Footcandles: the amount of light reaching a subject

Here are the types of light bulbs/lamps available for lighting fixtures:

1. Incandescent

  • GENERAL SERVICE
    General service light bulbs are inexpensive and readily available in a variety of wattages and shapes. They produce a yellowish-white light that is emitted in all directions. These light bulbs are available in either clear or frosted.
  • REFLECTORIZED
    Reflective coating inside the light bulb directs light forward, giving you better beam control than general service bulbs. Flood types spread light. Spot types concentrate light. Reflector light bulbs put approximately double the amount of light (footcandles) on the subject as General Service bulbs of the same wattage. Parabolic Reflector light bulbs control light more precisely. They produce about four times the light of General Service and are used in recessed lighting and track lighting. Weatherproof casing makes them suitable for outdoor spotlights and flood light fixtures.

2. Tungsten-Halogen

  • LINE-VOLTAGE LIGHTING
    PAR 16, 20, 30 and 38 reflectorized bulbs provide better beam control than regular incandescent PAR bulbs. Available in numerous spot and flood beam spreads, this line-voltage option is used in track lighting, recessed lighting, outdoor spotlights, and flood light fixtures.
  • T-3 Double-Ended light bulbs are available in a variety of base types and are used in wall sconces, torchiers, and outdoor flood lights. The direction of the light is controlled by the light fixture.
  • T-4 Single-Ended light bulbs come in both "mini-can" and "bayonet" base types and are used in wall sconces, bath brackets, torchiers, and pendants. The direction of the light is controlled by the light fixture.
  • LOW-VOLTAGE LIGHTING
    MR-11, MR-16 (Mini-Reflectors) provide excellent beam control. Available in numerous spot and flood beam spread, this low-voltage option’s miniature size permits use in smaller track lights, recessed lights, and outdoor spotlights.
  • PAR-36 provides superior beam control, especially over longer distances. Available in a broad selection of spot and flood beam spread, this low-voltage light is used in track lighting, recessed lighting, and outdoor lighting fixtures.
  • T-4 Bipin, also known as a "peanut" bulb, is a miniature lamp used in pendants, halogen desk lamps, and some track lighting fixtures. The direction of the light is controlled by the fixture.

3. Fluorescent
Compared to incandescent lights with comparable lumen ratings, fluorescent lights use 1/5 to 1/3 as much electricity and last up to 20 times longer. Compact types are used in smaller, trimmer fixtures such as recessed downlights, wall sconces, close-to-ceiling fixtures, and track lights. Screw-in types can be used in place of incandescents in standard lamp sockets. Available in a wide spectrum of colors, fluorescent light bulbs’ warm, white tones best duplicate the color of incandescent bulbs.

4. LEDs
Light-emitting diodes (LEDs) are energy efficient, environmentally-friendly light bulbs that use only 3-10 watts of electricity and last up to 10 times as long as compact fluorescents (far longer than typical incandescents). Although they are expensive, the cost is recouped over time in energy savings and low maintenance costs. LED lights are available in “cool” white light (ideal for task lighting) and “warm” white light (commonly used for accent lighting or small area lighting).

For more information about LED Lighting, click here.

5. High-Intensity Discharge (HID)
High-Intensity Discharge (HID) light bulbs have longer lives and provide more light (lumens) per watt than any other light source. Available in mercury vapor, metal halide, or high- and low-pressure sodium types, HID bulbs are used residentially for outdoor security and landscape lighting.10

This is just an overview of the wide variety of light sources that are on the market. For help in determining which light bulbs to use in specific applications, schedule a free design consultation with a Wolfers lighting expert.