Luminosity is the amount of visible radiant energy emitted by a source.
Luminosity is the amount of light emitted or reflected by an object or source. In more technical terms, it is a measure of the total magnitude of visible radiant energy emitted by a light source. Brightness is measured in units such as lumens ( lumens ) or candela, depending on the context.
The importance of luminosity in daily life is significant and covers various aspects. In homes, offices, streets and public spaces, it is essential to provide visibility and create safe and functional environments. In road marking and road lighting , it serves to guarantee the safety of drivers and pedestrians at night.
Exposure to natural light during the day influences the human circadian rhythm, affecting sleep, mood, and overall health. Artificial light sources are also used in therapies to treat mood disorders, such as seasonal depression. In fields such as photography , cinematography and design, luminosity is crucial to achieve optimal results. In addition, the technology of screens and electronic devices depends on it to offer an adequate visual experience.
In disciplines such as astronomy, the luminosity of stars and galaxies provides valuable information about their composition, distance and evolution. Efficient management of lighting systems, for its part, can contribute significantly to energy conservation and cost reduction .
Physical fundamentals
Light is a form of electromagnetic radiation visible to the human eye. It behaves both as a particle (photon) and as a wave , according to quantum theory. When light falls on objects, it can be reflected, refracted or absorbed, giving rise to visual perception.
Regarding the concept of brightness , we must point out that it should not be understood as a synonym for luminosity : unlike the latter, it is related to the subjective perception of luminous intensity , influenced by factors such as distance and angle of observation.
The units of measurement used in this context are the following:
- lumen (lm) : represents the total luminous flux emitted by a light source in all directions. It is a measure of the total amount of visible light. It is used to indicate the light output of bulbs, lamps and lighting devices in general;
- lux (lx) – Measures illuminance, that is, the amount of incident light per unit area. One lux is equal to one lumen per square meter. It is applied in architectural lighting, design and standards in various environments;
- candela (cd) – measures light intensity in a specific direction. A candela is approximately the amount of light emitted by a candle. It is used to describe the luminosity of directional sources, such as headlights, flashlights, and projectors.
The candela approximates the amount of light emitted by a candle.
Natural luminosity
Natural luminosity is a phenomenon that encompasses a wide range of visual characteristics in our environment. From the glow of the sun to the twinkling of the stars, this light manifests itself in various ways, influencing our perception of the world around us.
The sun, the primary source of luminosity , paints the sky with warm tones during sunrise and sunset, creating a glow that transforms the landscape. Its light reaches its peak at noon, illuminating intensely and generating clear shadows. On surfaces such as water, it reflects, producing sparkles and creating fascinating images. Additionally, refraction in the atmosphere contributes to effects such as the halo around the sun.
The contrasts between light and shadows create dramatic effects, such as backlit silhouettes or shadowy areas that give depth to the scene. The beams, often filtered by vegetation, add a touch of clarity in natural settings, highlighting specific elements. Moonlight, softer than sunlight, illuminates the night and creates a spectrum of soft shadows. In the night sky, stars twinkle, adding a magical element to the night landscape.
The tilt of the sun and its path across the sky affect the length of shadows and contribute to gradual darkening. Phenomena such as twilight at dawn or dusk add unique hues to the sky, with a mix of ambient light and soft shadows . In architecture, skylights allow natural light to enter, adding a touch of transparency and brightness to interior spaces.
The popular neon lamps stand out for their brightness and colors.
artificial luminosity
Artificial lighting has transformed the way we live, work and experience the world during nighttime hours. The different lighting sources that exist on the market offer a wide range of possibilities, each with its own characteristics and applications.
Let's look at some products that provide artificial luminosity:
- Incandescent bulbs : they have been a mainstay in artificial lighting. They produce a warm, soft light, but are less energy efficient compared to newer technologies. Incandescence is a classic method of generating light by heating a filament;
- fluorescent tubes : they emit light when a gas contained in the tube is excited by an electric current. They have been commonly used in industrial and commercial settings. They are more energy efficient than incandescent bulbs, have a longer lifespan and produce cooler light;
- LEDs (Light Emitting Diodes) : are semiconductor devices that emit light when an electric current passes through them. They have revolutionized lighting due to their efficiency and versatility. They consume less energy, have a long lifespan, and their ability to change color and adjust intensity makes them ideal for diverse applications, from home lighting to electronic displays;
- neon lamps : they generate light by discharging a noble gas contained in sealed glass tubes. Known for their brightness and striking colors, they have been used for advertising and decorative signs.
Two emerging technologies in this framework are smart lighting and OLED lamps . The first has evolved towards intelligent systems that allow programming, remote control and personalized settings, contributing to energy efficiency. Regarding OLED (Organic Light Emitting Diode) technology, these lamps use layers of organic materials to generate light, offering thinness and flexibility in their design.
Artificial lighting not only provides functional lighting but also influences the aesthetics and atmosphere of a space . The transition from classic technologies to more efficient and customizable options, such as LEDs, reflects the constant innovation in artificial lighting, improving our quality of life and environmental sustainability.