Vibration distribution measurements using interferometers have been evaluated by many researchers. We have used a laser diode interferometer to measure two-dimensional vibration distributions using a combination of phase-shifting and downsampling techniques. Our system simultaneously measured nanometer-order sinusoidal vibration distributions of two objects vibrating at different frequencies, using a charged coupled device camera with a slower frame rate than either of the two harmonic frequencies being measured. This is a cost-efficient and compact system capable of successfully measuring high-frequency vibrations without requiring expensive high-frame-rate cameras.