A conventional interferometer arrangement (e.g., test glass 12) is illuminated with white light and the resultant colored interference field is recorded by a color TV camera (16). The three output signals (R, G, B) of the color TV camera are directly, or after linear combination, converted into digital values and subsequently serve to address a digital storage (179) in which the phase difference of the interfering waves is stored for each R, G, B combination. The values read from storage are reconverted into analog signals and displayed as so-called pseudo-interference fringes on a TV monitor (18). A computer (19) for the further processing of the read data may be connected to the storage output.