Buying lighting products and lighting environments seems simple, but without knowing the lighting parameters, it is impossible to understand the reason for the price difference in different types of lamps. We may encounter products that are similar in some features, but have differences that are not noticeable, which prevents us from making the right choice. In this article from EDC, we have professionally examined the parameters of lighting and lighting. This guide will help you implement the best lighting for your environment.
Why is it important to know the parameters of lighting?
Knowing the parameters of lighting is important in several ways:
First, this knowledge helps us to choose the right light sources according to the needs of the environment, for example, we can determine how much light and what color is needed for a specific space.
Second, knowing the parameters allows us to make better decisions when purchasing lamps and lighting equipment and understand the difference in prices and different qualities.
By knowing these parameters, we can optimize energy consumption, prevent glare and inappropriate lighting, and ultimately create a comfortable environment.
Lighting Parameters
Next, we will learn about the lighting parameters:
Luminous Intensity
Luminous intensity or the unit of luminous intensity (Candela) is the amount of light emitted from a source in a specific direction. The luminous intensity formula is commonly used to calculate it more accurately in different environments. Luminous intensity is of great importance for the design of targeted lighting, especially where light needs to be focused.
Luminous Flux
Luminous flux is a measure of the total light power emitted by a light source. It is measured per unit of time and is represented by the symbol Φ and its unit of measurement is the lumen (lm).
However, this method cannot accurately express the full effect of a source’s light, because the light radiation is described without taking into account all wavelengths of visible light and the different sensitivity of the human eye to these wavelengths. In fact, the spectral sensitivity of the eye must be calculated in lumens.
For example, the radiation emitted by a light source with a power of 1 watt at the peak of the sensitivity of the human eye (wavelength 555 nm on the photopic spectral diagram) is equivalent to 683 lumens. In contrast, radiation emitted at other wavelengths, to which the human eye is less sensitive, will have a relatively lower luminous flux.
Power
Power refers to the amount of energy a light source uses per unit of time and is measured in watts (W). This parameter indicates the amount of energy a lamp or light source uses and has a direct impact on electricity consumption. Typically, lower-wattage energy-saving or LED bulbs provide the same level of brightness as older, higher-wattage bulbs.
Light Distribution
Light diffusion refers to the way light is scattered and distributed in an environment. This parameter determines how light is spread out from a light source to its surroundings. The type and shape of light sources and their lenses have a direct impact on the light diffusion pattern and can play a significant role in adjusting the brightness of an environment.
Uniformity of Light
Light uniformity refers to the degree to which light is evenly distributed over a given surface. This parameter indicates whether light is evenly distributed across the environment or whether some areas are brighter or darker than others. Proper uniformity is especially important in work and educational spaces to avoid unwanted shadows.
Brightness
Brightness is the amount of light emitted from a surface or light source and is measured in nits. This parameter describes the amount of light visible to the human eye. High-brightness light sources can cause glare, so it is important to set this parameter correctly.
Illuminance
Illuminance is the amount of light falling on a surface and is measured in lux (lx). This parameter indicates how much light is present per square meter of a given surface and is directly related to the quality and efficiency of lighting in a space.
Luminous Efficacy
Luminous efficacy is the ratio of luminous flux (lumens) to power consumption (watts) and indicates the efficiency of a light source. The higher this ratio, the more efficient and effective the light source. High luminous efficacy in LED lamps reduces energy consumption and electricity costs.
Electrical Efficiency
Electrical efficiency indicates the rate at which a light source converts electrical energy into light. A light source with high electrical efficiency can produce the most light with the least energy consumption and avoid energy waste.
Color Rendering Index
Color Rendering Index, or CRI, is a measure of a light source’s ability to reproduce the natural colors of objects. It is measured on a scale of 0 to 100. Light sources with a high CRI (greater than 80) are better suited for spaces where color accuracy is important, such as galleries and stores.
Light Color
Light color refers to the color temperature of a light source, measured in Kelvin (K). Low color temperatures (below 3,000 Kelvin) produce warm, yellow light, while higher temperatures produce cool, blue light. Choosing the right light color based on the environment and application helps improve visual comfort and the appeal of a space. Learn all about light color temperature in this link.
Glare
Glare occurs when high light intensity or contrast causes eye discomfort or reduced visual acuity. This phenomenon can be caused by high-brightness light sources or poorly designed fixtures. Controlling glare through the use of appropriate diffusers or lenses helps improve lighting quality.
Light Distribution Curve
A light distribution curve is a graph that shows the light distribution pattern of a light source in a space. This graph helps architects and designers to choose the best light source for specific applications and optimize the light distribution pattern.
Now that you are familiar with all the concepts and parameters of lighting, read the difference between lighting and illumination in this article.
Example to better understand lighting concepts
Suppose you want to light a large hall with LED lamps. You use a lamp with a power of 20 watts and a luminous flux of 1600 lumens, which indicates the total amount of light emitted by the lamp. The luminous intensity of the lamp is 150 candela, which means that the light is emitted with this intensity at a specific point. If the illuminance at the floor level of the hall is 500 lux, this indicates sufficient lighting for various activities in that space.
The light color of the lamp is 3500 Kelvin, which creates a warm and soft light, and its CRI is 90, so colors look natural and realistic under this light. The lamp’s luminous efficacy is 80 lumens per watt, which indicates the lamp’s high efficiency in converting energy into light. Its light distribution is uniform throughout the entire hall space, and its light distribution curve ensures that the light is distributed evenly throughout the hall. With this combination of parameters, you will have a bright environment with proper lighting.
Light measurement methods
Various instruments are used to accurately measure lighting parameters. One of the best tools for measuring light intensity is the luxmeter. This device accurately measures the amount of light shining on a surface. The correct selection and use of measuring devices can help to achieve greater accuracy in lighting design.
