This thesis investigates the lighting design theory Light Inside Out, which is the technique of shaping light toward a creation of lighting installation in performance utilizing a lighting installation in performance. It analyzes the differences between two lighting methods: 1) Illuminating a performance by theatrical lighting fixtures from outside the performance space and 2) Illuminating a performance with onstage lighting installations. Examples of lighting installation work done by several celebrated artists are also examined in order to demonstrate the unique creative advantage of using lighting installation in performance. Finally, a presentation of my design process for developing lighting installations for past works as well as my most recently developed designs for “ The Difficulty of Crossing a Field” and “Sunyata: Transfigurations in Silk” are included along with pertinent supporting materials, lighting installation process photos, and production photos. / text