The present technology relates to an imaging device, a method thereof, and an imaging element capable of controlling resolution of a detection image. Provided is a plurality of pixel output units that receives incident light incident without intervention of either an imaging lens or a pinhole and each outputs one detection signal indicating an output pixel value modulated by an incident angle of the incident light, and a signal processing unit provided so as to be associated with an area in which at least two pixel output units out of the plurality of pixel output units are formed that processes signals read out from the pixel output units formed in the area and obtains output pixel values. The present disclosure may be applied to, for example, an imaging element, an imaging device, an image processing device, an electronic device, a system and the like.