A radiance sensor includes a memory and a microprocessor. The memory stores non-transitory computer-readable instructions and adapted to store a plurality of electrical signals output from a photodetector array in response to electromagnetic radiation transmitted through a lenslet array and incident on the photodetector array. The microprocessor is adapted to execute the instructions to (i) determine irradiance of the electromagnetic radiation in a detector plane from the plurality of electrical signals, each electrical signal having generated by a respective one of a plurality of photodetectors of the photodetector array, and (ii) reconstruct, from the determined irradiance, the 4D-radiance in an input plane, the lenslet array being between the input plane and the detector plane.