A Cinema Luminance Range by the People, for the People: Viewer Preferences on Luminance Limits for a Large-Screen Environment

摘要

Display technology has been improving rapidly, in some areas faster than others. Televisions (TVs), tablets, and smartphones bring images to life through a combination of a brighter maximum luminance, a deeper black level, and/or a wider color gamut. Preference studies in this area confirm that viewers are looking for these increased capabilities in their displays. One such study performed on a TV-sized display at Dolby Laboratories found that to satisfy 90% of viewers, a luminance dynamic range of 0.005 to 20,000 cd/m would be required. Translating results from small displays to the larger screens of the cinema is not always straightforward because of the conjecture that large screens will influence a viewer’s preferences differently. For example, it is assumed that in comparison to a smaller display (i.e., TV), the brightness preference for the cinema is dimmer. This generalized assumption, however, includes multiple aspects such as contrast, increased flickering with higher luminance, and different fields of view. To investigate those aspects, we have conducted a study on viewer preferences for the cinema environment isolating the maximum diffuse luminance, the minimum luminance, and the highlight luminance from these other factors. We used a 6 kW cinema projector and 13 ft, 2.8-gain screen to produce a luminance dynamic range of 0.002 to 2100 cd/m, and concluded that the most demanding viewers prefer 22 f-stops of cinema dynamic range—double the number of f-stops of the existing dynamic range of the cinema.