A light compensating system in accordance with this invention comprises a plurality of light emitting devices, an image capturing device, and a processing device. The processing device is respectively coupled to the plurality of light emitting devices and the image capturing device. Each light emitting device is used for emitting light to illuminate a certain area in space. The image capturing device is used for capturing a first image, which can be defined as a plurality of image blocks. Each image block is affected by the light from at least one corresponding light emitting device. The processing device is used for analyzing a brightness value of at least one of the plurality image block and adjusting at least one light emitting device corresponding to the analyzed image block based on the brightness value.