A method is described for obtaining the azimuth and ellipticity of polychromatic elliptically polarised light as a function of wavelength, without the need for wavelength scanning. Elliptically polarised light with calculable polarisation was generated using a birefringent plate or a twisted nematic liquid crystal cell, and measurements of the azimuth and ellipticity of the light were made using the method. Good agreement with the calculated values was found, thus demonstrating the correctness of the technique.