Visual tasks lighting

Visual tasks lighting


projection light


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 scene in this visual field is interpreted by differentiating between the color of the surface, its reflection factor, and its illumination. Luminance depends both on the illumination of a surface and its reflection factor. Illumination and luminance are objective parameters, but the response to brightness is subjective.


When creating an environment that provides visual satisfaction, comfort, and good performance, it is important to balance the luminance within the visual field. Ideally, the luminance of the environment of a task should gradually decrease to avoid sharp contrasts.
The method of luminous flux for the design of lighting makes it possible to determine the average horizontal luminance of the worktop; it can be used to fix the average luminance values of the walls and ceilings of a room. It is possible to convert the average luminance values into average luminance values from the average reflection factors of the surfaces of the room.


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