360° videos can be viewed in an immersive manner with a head-mounted display (HMD). However, it is unclear how the viewing experience is affected by basic properties of 360° videos, such as how high they are recorded from, and whether there are people close to the camera. We conducted a 24-participant user study where we explored whether the viewing experience is affected by A) camera height, B) the proximity and actions of people appearing in the videos, and C) viewer position (standing/sitting). The results, surprisingly, suggest that the viewer's own height has little to no effect on the preferred camera height and the experience. The most optimal camera height situates at around 150 centimeters, which hits the comfortable height range for both sitting and standing viewers. Moreover, in some cases, people being close to the camera, or the camera being very low, has a negative effect on the experience. Our work contributes to understanding and designing immersive 360° experiences.

Interactive omnidirectional video (iODV) is a media format that allows the user to explore and interact with a 360-degree view of the recorded scenery. Recently, novel collaborative applications for presenting iODV content have emerged. Often their goal is to offer as immersive as possible experience to the users. Previous studies suggest that gender affects the §of immersion in virtual environments and other media, but there has been only little research on immersion in iODVs, and nothing in the context of collaborative interaction. In this research, we studied gender effect with participants (N=30, 15 pairs) performing a collaborative wayfinding task. Subjective data gathered with a customized immersion questionnaire showed statistically significant differences between male and female participants in Spatial Immersion and Involvement subscales. There were no statistical differences in Interaction, Realness, Physical and Auditory subscales. Several possibly affecting factors were observed during the task completion. Our results also indicate that performing interactive, collaborative tasks in iODV applications helps building a shared understanding between the users.