Abstract: Method for controlling the speed of horizontally rotatable supply turntables for tape material. In such a method for controlling the speed by measurement on a moving tape, especially on a film tape (3) in cinema show operation by removal from the inside convolution (4) of a reel (2) resting horizontally thereupon, the lead-in angle in front of a lead-in point (6) fixed in location is contactlessly measured by reflection of infrared light on both sides of the film strip (5) fed in. In case of deviations of the measurement signal from a nominal value, the reel drive is corrected. A dual infrared LED with reflection light barriers (11, 12) arranged offset in angle and height and approximately focused on the lead-in point (6) is used.