One step closer to a better experience: analysis of the suitable viewing distance ranges of light field visualization usage contexts for observers with reduced visual capabilities

Light field visualization technology offers a glasses-free 3D experience that may be enjoyed by multiple observers simultaneously. The overall visual experience depends on a multitude of factors, among which is light ray density. In case of horizontal-only parallax displays, it defines the smoothness of the horizontal motion parallax, which is crucial to visualization quality. However, the perceived light ray density naturally depends on the viewing distance; the farther the observer is, the fewer light rays may address the two pupils, with respect to a single point on the screen. Research on this topic has already been initiated and the first results are now available in the scientific literature. However, the experiment, similarly to the vast majority of research efforts regarding the perceived quality of light field visualization, is built on the participation of individuals that are screened for normal vision. Yet a notable portion of potential future users would not pass such screening, particularly the Snellen chart on visual acuity. In this paper, we investigate the suitability of viewing distances for the future use cases of light field visualization from the perspective of users with reduced visual capabilities. The subjective tests evaluate contexts of passive visual consumption, such as a cinematic experience or an exhibition of cultural heritage. The selected use cases are not only assessed by their natural viewing distance intervals, but by closer and farther distances as well. The output of the research aims to extend the social inclusion of potential systems and services of light field visualization.