We report far-infrared reflectivity spectra of the PbZr0.52Ti0.48O3 and copper doped PbTiO3 single-crystal films focusing on the electronic properties. The conductivity has been analyzed by the Drude-Lorentz model and in terms of dynamic interaction, which lends to a frequency dependent scattering rate and enhanced low-frequency carrier mass. Introduction of 0.5 mas.% Cu in PbTiO3 decreases effective mass from 3.5 to 1.5 near 200 cm(-1) and increases relaxation time compared with the undoped sample.