Pipilotti Rist's Homo sapiens sapiens, a video installation covering the entire vaulted ceiling of the baroque church San Stae was produced as official contribution of Switzerland for the 51st Venice Art Biennale. As a special effects artist, I had the chance to take part in most of the postproduction, as well as in the installation process. Subject of the work was the story of two women in an alternative version of Paradise prior to, or rather without, the original sin, set in a lush tropical backdrop. This theme called for an effortless, dreamy visual interpretation, where one of the chief stylistic devices employed was the consequent use of slow motion. The footage was recorded without the use of high speed video cameras, partly as DV, partly as 16mm. Simple frame blending or double printing would have ruined the effect we were looking for (you may observe the differences between the two methods by comparing the two halves of the videos on the right), so it became my task in the postproduction to create convincing slow motion digitally, by means of in-between frames with the aid of motion vectors. This process required a thorough anyalysis of all movement in the picture, plus lot of 'handiwork'. The automatically estimated motion vectors needed to be checked between every single frame, and in many cases manually adjusted, to avoid jumps and get rid of artifacts. The second dragon to slay was the adjustment of the final work to the irregular geometry of the church. This was achieved by an interplay of using multiple masks, geometrical meshes and fine-tuning on the beamers themselves. The picture was first sliced into four quarters, then each part was assigned to one of four beamers covering a quarter of the ceiling. They were then matched to meet each other seamlessly in the middle, and blend into the rest of the church by following its architecture on the borders.
TIME STRETCH
