Abstract: The invention pertains to a system comprising: a source to generate a pulsed radiation pattern; a detector; a processor to process data from the detector when radiation is reflected by an object; a synchronization means interfacing between the detector and the source; wherein: the detector is synchronized with the source so that radiation to be processed is detected only during the pulses, the processor determines a characteristic of the object by determining displacement of detected spots with reference to predetermined positions, the source emits monochromatic light and the detector is equipped with a bandpass filter and optics arranged so as to modify an angle of incidence onto said filter to confine light to a predetermined range around a normal of said filter, said optics comprising an image-space telecentric lens.