A Simple Explanation of Luxury

What is the Lux?

The Lux (lx) is a unit of measurement that evaluates light intensity: when 1 Lux is reached, it means that an area of 1 m² is uniformly illuminated by 1 lumen.

While the light output of a source is expressed in lumens, the Lux quantifies the light reaching a given surface, such as a table, for example.

However, since the lux value is influenced not only by lumens, but also by the light intensity (measured in candelas) of the bulb, the distance to the illuminated surface, and the general configuration of the space, it is generally not included in product specifications.

How are Lux calculated?

To obtain a precise measurement of light intensity, a lux meter is required, as light reflections on walls and the ceiling also impact the value. An approximate estimation of lux can be made by taking into account:

The candela value of a light source.

The distance between the light source and the illuminated surface.

The formula for calculating Lux is as follows:

Lux = Candela / Distance² (in meters)

For example, a bulb with a beam angle of 90° and a brightness of 320 lumens is equivalent to approximately 170 candelas. If it is suspended 80 cm above the table, this will result in approximately 270 Lux of illumination.

Light intensities of artificial light and natural light

In professional environments, the calculation of illuminance is required according to the indicative values of the European standard DIN EN 12464-1 "Lighting of work places - Indoor work places." Other specific regulations may also apply, such as the ASR A3.4 standard "Lighting," as well as specific rules for public lighting. However, no regulations are in place for private residences.

In different rooms

A comfortable brightness level for living spaces such as the living room, the bedroom, or the dining room is generally around 300 Lux, often achieved through a ceiling light or pendant light.

For specific activities

For activities requiring strong light, such as sewing or reading, about 500 Lux are considered ideal. Additional light sources such as floor lamps or table lamps are then used.

A dimmed ambiance

To create a warm atmosphere in the living room, the light intensity is often reduced, for example to about 50 Lux.

Home office lighting

Lighting of 500 to 1,000 Lux is recommended for the home office. Ceiling lights with a direct light component or desk lamps are appropriate choices.

Night lighting

For nighttime orientation, a brightness of 10 to 50 Lux is sufficient to avoid disrupting sleep. LED strips are an interesting aesthetic option.

Natural daylight

Natural daylight varies in intensity, reaching up to 100,000 Lux on a sunny summer day, about 20,000 Lux in cloudy weather, and about 3,500 Lux under an overcast winter sky. At twilight, it decreases to about 750 Lux, and during a full moon night, it is about 0.25 Lux

Setting light and motion sensors

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Many devices, such as those integrated into outdoor wall lights, can be adjusted to activate at a certain light intensity, measured in Lux. Usually, this value is set to about 10 Lux, but it is important to check that the light turns on correctly. The sensitivity can be adjusted from a few lux up to 1,000 Lux or 2,000 Lux, depending on personal preferences and environmental conditions. This adjustment is generally done using a key on an adjustment screw, which makes subsequent adjustment quite simple. The instructions provided with the device offer precise indications on the adjustment procedure.