Lighting system for dim ambience

A lighting system for dim ambience, comprising:

• at least one light source module, implemented in the ambience to provide illumination, wherein each of the light source module has a plurality of light emitting units, each of the light emitting units is respectively controlled to generate a luminance;
• a luminance detecting unit, detecting a photopic luminance;
• a processing and operation unit, externally receiving a light source information of the light source module to calculate out a luminance ratio (S/P), which is defined by a ratio of a scotopic luminance (S) to the photopic luminance (P), a mesopic luminance is calculated out according to the photopic luminance and the luminance ratio, when the photopic luminance is less than a dim-light setting value, a power control information is obtained by a fitness operation with a given condition set, wherein the power control information is corresponding to an optimized mesopic luminance after the fitness operation, wherein the given condition set composed by referencing to a mesopic luminance parameter, a photopic luminance parameter, and a power parameter;
• and a control unit, receiving the power control information to adjust the luminance of the light emitting units.