Various embodiments provide a method for determining a wave form of a lamp current for operating a discharge lamp of a projection arrangement having a color wheel and a ballast, such that a polarity of the electrodes is commutated in accordance with a commutation scheme of the wave form. The method involves providing a wave form having a commutation scheme and checking whether operation of the discharge lamp satisfies one criterion relating to a lifetime of the discharge lamp or a flicker amplitude of the projection arrangement. If the criterion checked is satisfied, checking whether operation of the discharge lamp satisfies the other of the two criteria is carried out. If at least these two criteria are satisfied, the wave form is stored in a memory of the projection arrangement and provided as the predefinable wave form at the ballast for the discharge lamp.