Light intensity, measured in Lux
Lux is the measure of the brightness at a particular location. Since the calculation depends on several individual factors, this value is not to be found on luminaire packages and if so then usually only as a guideline (calculation on one meter distance).
Even though this term might not be understandable for the average consumer, with this value the interior designers can determine whether the light is sufficient e. g. to illuminate a desk the right way. For laboratories and public places precise guideline values are required in the interests of occupational health and safety. These guideline values are used to determine whether a workplace, paths or public spaces are perfectly illuminated. This ensures that employees don’t damage their eyes in the long term because the workplace is insufficiently illuminated.
These guideline values are defined in DIN 12464 part 1 for workplaces and interiors of different sectors. For the illustration above we have selected some values for you to refer to normal residential situations.
Important: these are values defined by the requirements of visual tasks, activities and the type of space. This is supposed to be a guide of how high the light intensity should be. However it is always important which requirements each person has personally, thus there’s no general recommendation for living areas.