A couple of "single use camera" and a craft tape, that's all.Put the cameras tightly together with tape, as shown below.Choose an object, and press two shutters at the same time,that's a knack! If you press each shutter at a different moment, the moving objects are recognized as shifting forward or backward, but don't mind, it is the taste of hand-made.Theprinted photos may be too big to see by a parallel view method. In that case, pile up a half of the print.