An improved three-dimensional imaging system for imaging an object including a plurality of resolvable elements includes: an amplitude modulated radiation source for transmitting radiation to the object (28); at least one photoelectric image detector (12, 14, 16); means for synchronously enabling the at least one detector during at least three portions of the period (37, 38, 39) of the modulated radiation source for detecting the radiation reflected from the object (36); means for calculating the phase angle between the transmitted radiation and the reflected radiation (40); and means, responsive to the means for calculating the phase angle for calculating the range of a plurality of elements of the object with respect to each other (40).