A technique has been developed for producing freely falling pairs of water drops with unequal radii. Radius ratios as large as 10 to 1 can be obtained with drops having radii in the range 0.1–1.0 mm. Continuous production of drop pairs is possible, with the desired repetition rates selected by electronic controls and unwanted drop pairs deflected out of the observation volume. Successive pairs, thus produced, are sufficiently identical that a sequence of photographs has been obtained with an effective elapsed time between exposures of 100 &mgr;sec, the equivalent of 10 000 frames/sec in terms of high speed photography.