Technical Lighting: Introduction

What is technical lighting? It is an art that combines technical knowledge, personal taste and emotional aspects.

What is technical lighting

Lighting technique is the study of the application of lighting artificial indoor and outdoor environments.

The biggest challenge of who “draws” the light is getting good subjective results. Light you do not see, you feel!


A good result depends on several factors : type of environment, length of stay in that space, architectural language , composition of artificial light with natural light, customer profile and the final cost.

The light itself is invisible, what we see is the illuminated object and this is exactly why the light is directly related to color and texture that this object has. As each person has a different sensitivity from each other (for color and amount of light), the psychological feeling transmitted will be different for each individual.



What is “Light”

Light is an electromagnetic wave , that besides the visual effects (production of light and colors),emits ultraviolet radiation (UV) . These radiations are responsible for tissue fading (curtains, clothing, sofas), wood (furniture, flooring) and other objects exposed to light. Another emitted radiation is infrared (IR or IR) , which is responsible for the production of heat. As sunlight emit such radiation, the lamps (to a lesser or greater degree, depending on the model) emit UV and IR radiation.

Below is a chart that shows how we perceive the solar radiation that reaches the Earth:

  • Ultraviolet (UV) – 3%of the total radiation (in addition to the effects mentioned above related to decoration, is also responsible for skin cancer and premature aging);
  • Infrared (IR or IR) – 55%of the total radiation (solar heat responsible);
  • Visible Light – 42%of total radiation (affects the sense of sight, so we see colors).

Efficient use of light in External Areas

Perhaps many have not heard of light pollution, which is the irrational use of lighting systems , causing undesirable impacts on the environment (especially in outdoor areas), such as damage to the flora – ex .: non – flowering plants, as the duration of the night is shorter; disorientation of animals ex .: misfit reproduction and migration of species. In addition to excessive energy consumption.

It is crucial to know to plan and use lamps, lighting fixtures and accessories properly to get the best result . The image below shows four examples for lighting outdoors:

  • 1st and 2nd images reveal twoinefficient systems, because there is a wide dispersion of light being launched into the sky and therefore is not being harnessed;
  • 3rd and 4th images present twoefficient systems because the light is directed downward, illuminating the area needed, that is, where are people and vehicles.


Efficient use of light in Internal Areas

This same scheme presented can be thought to internal areas. There are models of lamps and fixtures that produce these same effects on the environment, but for other purposes.

  • 1st and 2nd images: in this new situation,not we consider these systems as inefficient , because usually we have a white ceiling and with a simple right foot (2,55cm) that makes the light “move” up is refletita for all the environment, providing good lighting –
  • 3rd and 4th images: these two examples, indoors, show how to createlighting effects. A targeted and prominent lighting is intended to create a scenario (bring a different effect)or to assist in visibility (bringing more light into a specific point , important for carrying out various tasks or simply drawing attention to look at a certain point). These effects do not have the purpose of producing general lighting in the environment internal , so if used for this purpose, shall be deemed inefficient.


In short, it is very important to know the models of lamps, fixtures and fittings to create a comfortable lighting and sustainable , achieving the desired objectives without waste of energy.


Color Temperature

Every lamp has a certain color temperature , i.e., each lamp model emits a light with a certain color. These colors have been developed in accordance with the colors emitted by the sun (natural light): the light shade white is seen at noon, while the yellow and orange hue lights are seen at dusk.

The color temperature is measured through Kelvin unit , which may vary 2000-6100 Kelvin. Where:

  • Yellow Light:  “Hot Light”
  • Color temperature:  less than or equal to 3,000 Kelvin
  • White Light:   “White Light Natural”
  • Color temperature: greater than 3,000 and less than 6,000 Kelvin – (5,800 Kelvin is the color temperature of light obtained with sun at noon in the open)
  • Blue-Violet Light:  “Cold Light”
  • Color temperature: not less than 6,000 Kelvin


Color temperature – Lamps

The following chart illustrates very well the different temperatures of color and shows the corresponding lamps models. (In the same graph is the Color Rendering Index, which just below the chart will be clarified).

  • Lamps 2800-3000 kelvin – have white-yellowish
  • Like:  coziness;
  • Use:  ideal for homes, bars, upscale restaurants – is suitable for any places where you want to get the feeling of comfort and tranquility;
  • Improper use:  as this yellowish provides relaxation and even sleep, should not be used in places that require a good rhythm of work, because they will reduce the yield. Examples of sites that should not use it: offices, factories, workshops, ateliers, popular restaurants – environments that have an accelerated pace of work / production.
  • Lamps from 4,000 to 5,000 kelvin – have bluish-white hue
  • Like:  stimulus;
  • Use: ideal for environments that present a fast – paced work / production, such as such as offices, medical offices, dental, industries, workshops, ateliers, popular restaurants, fitness centers and residential and industrial kitchens;
  • Improper use: in bedrooms, living rooms, dining rooms, spas, hotels, entrance halls – places that need a relaxing environment.


Color Rendering Index (CRI)

It is the ability of the light source has to faithfully reproduce the colors of the illuminated objects . By it The index can be from 0 (zero) to 100 (one hundred) , and the lower the value, the worse the color reproduction; and the higher the value, the color closest to the real, i.e., as the color is seen to be exposed to sunlight.


Lamps models and his IRC

  • IRC – 85:  most compact fluorescents – good level of color reproduction;
  • IRC – 90:  Fluorescents last generation – optimal level of color reproduction;
  • IRC – 100:  Incandescent (dichroic, ordinary incandescent, PAR Halogen and double bipino) – excellent level of color reproduction.

* Tip: whenever you need to see very well the task being performed (like makeup, choose clothes, hand drawings), choose lamps with good color reproduction.



Luminous flux: Energy Quantity

According to Wikipedia the Luminous Flux is ” total radiation emitted in all directions by a light source or light source that can produce visual stimuli .” The flux is measured in lumens , which defines the amount of radiant energy produced and emitted by a light source.

As we know, there are on the market many lamps, and each model emits a certain amount of energy. So each lamp model illuminates the environment in a way. The efficiency of the lamps is obtained by the ratio between the quantity of irradiated lumens and the energy consumed. Thus, the more lumens per watt, the higher the lamp efficiency.


Illuminance and luminance

The luminance indicates the amount of light (see that focuses on a surface , and theluminance indicates the amount of light (luminous flux) that is reflected by a surface . The amount of illuminance has the unit of measure Lux, which is one (1) Lumen per square meter.



Every room has a certain amount of illuminance as the activities undertaken at the site. Therefore, the lighting design should follow the rules of ABNT, which preevêm the ideal illuminance for the site.


The illuminance (lux amount) for each type of activity

CLASS A   – areas of continuous use and / or performing simple tasks

  • 20 |30 | 50 lux:  Public Streets and Parking Lots
  • 50 |75 | 100 lux:   Environments little permanence
  • 100 |150 | 200 lux:   Deposits
  • 200 |300 | 500 lux:  Gross Works and Auditoriums

CLASS B   – working areas in general

  • 500 |750 | 1,000 lux:  normal work – ex .: Offices and Factories
  • 1,000 |1,500 | 2,000 lux:  Special work – ex .: Record, Inspection, tissue Industries

CLASS C   – areas with detailed visual tasks

  • 2,000 |3,000 | 5,000 lux:   Continuous work and accurate – ex .: Electronics
  • 5,000 |7,500 | 10,000 lux:   Work that requires a lot of accuracy – ex .: electrical and electronic boards
  • 10,000 |15,000 | 20,000 lux:   Special thorough work – ex .: Surgery



After meeting the illuminance level for a given function / activity, you can perform the luminotécnico calculation to know the amount of lamps and fixtures necessary for optimal lighting. Remember that the physical characteristics of the site (length, width, ceiling height and height workplan), colors of the walls and furniture, as well as the type of material used, should be taken into account.


Know the reflection of light levels as the Color and Material

  • White: 70 to 80%
  • Yellow:   50 to 70%
  • Grey:   20 to 50%
  • Black:   3 to 7%
  • Wood:  70 to 80%
  • Rock / Stone:   50 to 70%
  • Brick:  20 to 50%
  • Concrete:  3 to 7%



To make a good lighting design is required the knowledge of luminotécnicos concepts, lamps, lighting fixtures and have sensitivity about the psychological aspects generated by the light in people.


The lighting project is a specific job that requires a lot of work and detailing .