A distance from an apparatus to at least one object is determined by generating a first signal and generating light modulated by the first signal to be emitted from the apparatus. Light reflected by the at least one object is detected using a Time-of-flight detector array, wherein each array element of the Time-of-flight detector array generates an output signal from a series of photon counts over a number of consecutive non-overlapping time periods. The output signals are compared to the first signal to determine at least one signal phase difference. From this at least one signal phase difference a distance from the apparatus to the at least one object is determined.