The Investigations of this article focus on the response of Al2O3:C and Al2O3:C,Mg radioluminescence films for medical dosimetry in various MV photon beams. A dosimetry system was configured using a scientific camera, attached to the head of the linear accelerator (LINAC), facing the beam’s isocenter, where the films were placed. By using the appropriate filter and lens it is possible to measure real time two-dimensional dose-rate distributions. The key findings are that Al2O3:C,Mg films present a clear advantage compared to Al2O3:C ones, with no interference from afterglow, better film uniformity, high spatial resolution and suitability for small field beam dosimetry, while giving overall good dose-rate response in Flattening Filter (FF) and Flattening Filter Free (FFF) modes. The results show that our system can be used for planar real time dose rate assessment in medical photon dosimetry with manageable correction factors.