3D movies are calibrated to meet a certain screen brightness standard. Therefore, what would be the consequences on the quality of the 3D experience for spectators watching a 3D movie when movie theaters do not respect this standard? First, we attempted to better understand which factors were important for a spectator by conducting an experiment where participants watched a 3D movie and filled out an exploratory questionnaire. Then, we aimed to investigate the link between image brightness loss and the quality of the 3D experience as perceived by the spectator. First results show no perceived difference in the quality of the 3D experience between a normal brightness and a brightness decreased by 10% for four factors, i.e. (1) the appreciation of the movie, (2) the content of the movie, (3) the 3D quality of the movie, and (4) the quality of the 3D experience in general.