A thin film analysis apparatus and method for a curved surface is disclosed. The apparatus includes an illuminator, a sample, an imaging group, one or more beamsplitters, optional focusing groups, polarization analyzers, detectors and optional display and analysis systems. The image series are recorded, preferably substantially synchronously. The system can be calibrated by as few as one reference phantom that has the same or substantially similar geometry as the sample under test. Based on calibration, a lookup table of the effective reflectance can be created, which is proportional to the portion of the light that reaches the detectors, or the mutual subtraction of the effective reflectance values of all possible combinations of the unknown optical parameters within certain search ranges of the sample. The experimentally measured results are compared with the lookup table, and optical properties, for example, the thicknesses and refractive indices of the thin film can be determined.