Definition of Candela

Candela is a unit of measurement for luminous intensity in the International System of Units (SI). It quantifies the amount of light emitted by a source in a specific direction. Essentially, candela measures the brightness of a light source as observed by the human eye.


The phonetic pronunciation of the keyword “Candela” is: /kænˈdɛlə/

Key Takeaways

  1. Candela is an international lighting company known for its modern designs and innovative technology.
  2. They offer a wide array of products, including LED lighting solutions, indoor and outdoor lighting fixtures, and smart lighting systems.
  3. Candela is committed to sustainability and energy efficiency and aims to reduce the environmental impact of their products through eco-friendly materials and manufacturing processes.

Importance of Candela

The technology term Candela is important because it plays a crucial role in quantifying and measuring light emitted by a source, which is necessary to assess the performance of various illumination devices.

As the standard unit of luminous intensity in the International System of Units (SI), Candela allows for consistent comparisons of brightness within a specific direction among different light-emitting objects, such as LEDs, light bulbs, screens, and other displays.

This unit serves as an indispensable part of designing, manufacturing, and evaluating lighting systems, as well as assisting in improving their energy efficiency and visual comfort.

Furthermore, understanding Candela values is essential for professionals such as architects, engineers, and designers, who often rely on this measurement to create well-lit spaces, ensure proper visibility, and maintain safety standards across a wide range of applications.


Candela is a vital term to understand when delving into the world of lighting and illumination. Its purpose is to provide a universally recognized unit of measurement for luminous intensity, allowing individuals in various industries to accurately quantify the brightness emitted by light sources.

By standardizing this measurement, the candela ensures consistent characterization of lighting products and aids designers, engineers, and consumers alike in selecting the proper lighting solutions to accomplish their objectives. One can observe candela being put to use in several applications, including the design and testing of automotive headlights, stage and architectural lighting, and even in evaluating the efficiency of LEDs.

A clear comprehension of the term allows experts to optimize any light source for user safety, comfort, and visual acuity. As a practical example, streetlights calibrated with an adequate number of candela will cultivate a safe environment for pedestrians and vehicles during nighttime, while simultaneously minimizing energy consumption.

Overall, candela plays an indispensable role in the development of various lighting technologies to suit the dynamic needs of our modern world.

Examples of Candela

Candela is a unit of measurement for luminous intensity, which defines the perceived brightness of a light source. While it does not refer to a particular technology, it is applicable to various lighting technologies used in multiple real-world scenarios. Here are three examples:

LED Lighting: LED (Light-emitting diode) lights are commonly used in residential, commercial, and street lighting applications. Their luminous intensity is often measured in candelas to provide accurate information about their brightness. For instance, traffic signals and airport runway lights employ high-intensity LEDs with a specific number of candelas to ensure proper visibility and safety.

Automobile Headlights: Modern car headlights, such as halogen, xenon, and LED-based systems, are designed to provide sufficient illumination for drivers. The brightness of these headlights is measured in candelas, allowing manufacturers and consumers to compare different headlight systems based on their luminous intensity. This helps ensure a consistent level of brightness and visibility across various driving conditions.

Digital Displays: The brightness of television screens, computer monitors, and smartphones is an essential aspect of their performance. The luminance (measured in candelas per square meter, or nits) of these displays is a crucial factor in determining their overall image quality, contrast, and visibility under different ambient light conditions. Manufacturers often use the candela as a measurement unit to provide consumers with accurate information about their products’ brightness.

FAQs on Candela

What is Candela?

Candela is a unit of measurement for luminous intensity and represents the amount of light emitted by a source in a given direction. It is part of the International System of Units (SI) and is denoted by the symbol ‘cd’.

How is Candela defined?

One candela is defined as the luminous intensity of a light source that emits monochromatic radiation at a frequency of 540×10^12 Hertz with a radiant intensity of 1/683 watt per steradian in the given direction.

What is the significance of Candela in lighting?

Candela is significant in lighting as it helps understand the light output of various sources like lamps, bulbs, and fixtures. It provides a means to effectively compare the brightness of different light sources and choose the appropriate one based on the intended application.

How is Candela related to other lighting units like Lumen and Lux?

Lumen is a unit of measurement for the total amount of visible light emitted by a source, while Lux measures the illuminance or the quantity of light on a surface. Candela is related to Lumens and Lux, as these units all help describe different aspects of light and its behavior. The relationship can be summarized as: Lumens measure the total light emitted, Candela measures the intensity of light emitted in a specific direction, and Lux measures the amount of light received by a surface.

How do I convert Candela to Lumens or vice versa?

To convert Candela to Lumens, you need to know the beam angle of the light source. The formula is: Lumens = Candelas x (2 x pi x (1 – cos (beam angle / 2))). To convert Lumens to Candelas, you need to use the reverse formula: Candelas = Lumens / (2 x pi x (1 – cos (beam angle / 2))). The beam angle is usually provided by the manufacturer of the light source or can be measured using specialized equipment.

Related Technology Terms

  • Luminous Intensity
  • Light Measurement
  • SI Unit
  • Light Emitting Diodes (LED)
  • An international standard for brightness

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