Task-ambient lighting refers to a general uniform lighting system supplemented with local lights (eg. desk lamps).

Task-ambient design approaches save energy when compared with most general lighting strategies. For example, lighting fixtures might be concentrated over work areas, while an indirect lighting system provides low levels of general illuminance. Thus, average light level for the room may be lower, and the number of required light fixtures may be reduced. This design strategy usually requires point calculations to insure that lights are correctly located to produce the lighting level and quality necessary for performing visual tasks at the needed locations.

General lighting is still the most widely practiced lighting design approach as it is cheaper and easier to do. However, task-ambient systems are becoming more attractive with the development of new lighting equipment and easy-to-use point calculation computer programs, and with rising electrical energy costs.

Information that will assist the designer is selecting the most appropriate task lighting source includes: the nature of the visual task(s) being performed in the space to be lighted; the contextual data relating to the space, which includes information about the reflectivity of the walls, ceiling, floor and furniture; factors that might affect visual comfort, such as direct glare from windows, existing lighting fixtures, or other internal sources; and age(s) of the occupant(s) of the space and the level of illumination required for the tasks being performed regularly;

Task ambient lighting provides the exact amount of lighting required to perform a specific task as well as the most energy-efficient lighting available. In a research lab, this could mean lighting fixtures concentrated directly over the work space, providing the lighting levels required for the tasks being performed, while an indirect lighting system provides relatively low levels of ambient (general) illuminance for the remainder of the space. If the average light level were to be calculated for this space, it would be lower than in a traditional design, but the occupants would most likely report a high level of satisfaction with the system.