Common Lighting Terms - Glossary

Lighting is a multifaceted field with its unique terminology and technical jargon. Grasping these terms can empower you to make the right decisions when selecting lighting products and fixtures for your home or business. Below is a glossary of prevalent lighting terminology, each coupled with a concise explanation:  

• Efficacy: Efficacy symbolizes the efficiency of a light source, measured in lumens per watt (lm/W). Superior efficacy signifies that the light source generates more light while utilizing less energy, thereby being more energy-efficient.
• CRI (Color Rendering Index): CRI quantifies how accurately a light source renders colors. A loftier CRI implies that colors appear more vibrant and authentic under the respective light source.
• Color Temperature: This term measures the perceived "warmth" or "coolness" of a light source, denoted in degrees Kelvin (K). A lower color temperature, such as 2700K, suggests a warm, yellow light, while a higher color temperature like 5000K, infers a cool, white light akin to sunlight. Even higher temperatures, say 6000K, yield an extremely cool, blue light.
• Drivers/Ballasts: These are crucial components that modulate the current supplied to a lighting fixture, ensuring it operates safely and optimally.
• Lamp Beam Angle: This term describes the spread of light emitted from a lamp or bulb. A broader beam angle signifies the light is dispersed over a larger area, while a narrower beam angle implies a more concentrated light dispersion.
• Wattage: Wattage measures the power consumption of a lighting source. Elevated wattage denotes that the lighting source consumes more electricity and subsequently produces more light.
• LED (Light Emitting Diode): LEDs are semiconductor devices that emit light when an electric current passes through them. Offering superior energy efficiency, longevity, swift switching, and durability, LEDs outshine traditional incandescent bulbs. Commonly found in energy-conscious applications like traffic lights, commercial and industrial lighting, architectural lighting, and electronic devices including televisions, computer monitors, and smartphone screens.
• LM-79: This standard, established by the National Lighting Product Information Program (NLPIP) and the Illuminating Engineering Society of North America (IES), outlines the procedures for measuring and documenting the photometric performance of LED lighting products. The purpose of LM-79 is to offer manufacturers a consistent and reliable method to report product performance, facilitating consumers in comparing and evaluating different products.
• Certifications: Marks like UL (Underwriters Laboratories) signify that a lighting product or fixture has undergone rigorous testing and adheres to certain safety and performance benchmarks.
• Life Span: This term refers to the predicted operational duration of a lighting source before failure or the necessity for replacement arises.
• Optimum Temperature Range: This defines the temperature spectrum within which a lighting source performs optimally. Using a lighting source outside of its optimum temperature range could impair its performance and lifespan.
• Foot Candles: This unit measures the intensity of light on a surface. It is calculated as the light falling on a surface from a single candle positioned a foot away.
• Lux: This unit gauges the intensity of light in a given area. It's computed as the light falling on a surface from a source of one candela placed one meter away.
• Lumens: Lumens is the unit for measuring the total light output produced by a lighting source. It's a handy tool for comparing the brightness of different lighting products.
• Light Loss: This term refers to the degradation in light intensity over time. LEDs experience minimal light loss compared to other lighting types, ensuring their brightness remains consistent for longer.
• Room Reflectivity: This refers to a room's capacity to reflect light. Higher reflectivity means more light bounces off the room's surfaces, potentially enhancing the room's brightness.
• Mounting: Mounting pertains to the method of attaching a lighting fixture to a surface. For instance, flush mount fixtures are directly fastened to the surface, while hanging fixtures are suspended from the ceiling.
• Luminaire: A luminaire, often referred to as a light fixture, is a complete lighting unit. It includes the lamp, housing, connection and all components to distribute light, position and protect the lamps, and connect the lamps to the power supply.
• Ambient Lighting: This is the general illumination within a space. It provides an area with overall light, and its sources are often fixed and spread throughout a room.
• Task Lighting: This type of lighting is designed to help you perform specific tasks, such as reading, cooking, homework, games, or balancing your checkbook.
• Accent Lighting: Accent lighting is primarily decorative, intended to highlight pictures, plants, or other elements of interior design or landscaping.
• Daylight Harvesting: This is the practice of making optimal use of natural daylight in buildings in order to reduce the need for artificial lighting.
• Light Pollution: This refers to excessive, misdirected or obtrusive artificial light. It can cause a range of issues, from obscuring the stars at night to impacting wildlife and ecosystems.