IoT developments make shared systems, such as lighting systems, increasingly connected. From an interaction perspective, this offers opportunities for personal control. Especially for lighting, the benefits of personal control have been underlined by research. However, how to design interfaces that realise these potential benefits is much less investigated. This paper presents a long-term qualitative study in which three interfaces for a shared lighting system are evaluated by 17 people working in an open plan office. The interfaces are designed to vary on a number of characteristics, including the distribution over space, interaction modality, and sequence of interaction. Based on the results, we provide new insights in the impact of interface characteristics on lighting use and experience. We find, i.a., that having an interface on a personal multi-purpose device or on a central interface solely dedicated to lighting, influences whether people make individual or more collective lighting adjustments and decisions.