Visual tasks lighting

Measurement In many workplaces, it is not necessary to illuminate all areas at the same level. Localized or local lighting may provide some energy savings, but whichever system you choose, you will ensure that variations in lighting in a room are not too strong. Instruments used to measure illumination and luminance have spectral responses that differ from those of the human visual system. These answers are often corrected using filters. If filters are integrated, the instruments are said to be color-corrected. The lux meters have an additional correction that compensates for the direction of incident light arriving at the sensing cell. Lux meters capable of measuring illumination accurately from different directions of incident light are called cosine correction. Measurements of the glare index; The system most frequently used in the United Kingdom, with variants in other countries, consists essentially of a two-step process. The first step establishes ...

Optimum lighting conditions for visual comfort and performance When considering lighting conditions for visual comfort and performance, it is recommended to consider factors that affect the ability to distinguish details and that fall into two categories: observer characteristics and characteristics of the task. The characteristics of the observer. They understand: ·          The sensitivity of the individual's visual system to size, contrast, exposure time; ·          Transient adaptation characteristics; ·          Predisposition to glare; ·          Age; ·          Psychological and motivational characteristics. Characteristics of the task. They understand: ·          Configuration of details; ·   ...

Optical control of lighting If a bare lamp is used in a fixture, the distribution of light may not be acceptable and the system will certainly not be economical. In this type of situation, the bare lamp is likely to be a source of glare for the occupants of the room and, even if some of the light reaches the worktop, the efficiency of the installation can be seriously affected. Reduced because of the phenomenon of glare. It is obvious that a light control system is necessary; the most frequently used methods are described below. The opaque screens If a lamp is installed in an opaque enclosure with a single opening to allow light to pass through, the distribution of light will be limited. The reflection This light control method uses reflective surfaces that can vary from a very matte appearance to a highly specular or mirror-like appearance. It is more efficient than opaque screens because scattered light is recovered and redirected where it is needed. ...

Visual tasks lighting The ability to distinguish details in the visual field - visual acuity - depends very much on the observer's task size, contrast, and visual performance. An increase in the quantity and quality of light greatly increases visual performance. The effect of lighting on the execution of the task is influenced by the size of the smallest detail of that task and the contrast between the task and its immediate environment. This shows us the effect of the illumination on visual acuity. When considering the lighting of a visual task, it is important to consider the ability of the eye to perform the visual task quickly and accurately. This combination is called visual performance. This shows the main effects of lighting on visual performance for a given task. In lighting, it is essential to predetermine the illumination reaching a work surface. However, the human visual system is sensitive to the distribution of illumination in the visual field. The...