High-refractive-index materials LaF3, NdF3, and GdF3 and low-refractive-index materials MgF2, AlF3, and Na3AlF6 single thin films are deposited by a resistive-heating boat at different depositing rates and specific substrate temperatures on single crystal MgF2 substrates. Transmittances of all fluoride thin films are measured using commercial spectrometer in the ambient atmosphere and under vacuum using synchrotron radiation instrument in the wavelength region from 190 to 500 nm. The optical constants of these materials are determined by envelope method and iterative algorithm on the basis of transmittance measurements.