Specific to your query, "HDRi" (High Dynamic Range imaging) is often referenced in professional VFX workflows for this film. Lighting artists at Digital Domain used HDRi to capture the actual lighting on set, which allowed them to light Benjamin’s digital head to match the live-action environment perfectly. Core Film Information David Fincher
: In later parts of the film, Lola VFX performed "digital facelifts" to youth-enize both Brad Pitt and Cate Blanchett as they moved through their prime. Critical Legacy The Curious Case of Benjamin Button -2008- HDRi...
Before diving into the technical specifications of the HDRi release, one must understand the source material. Benjamin Button is not an action film; it is a mood piece. It relies on the subtle weathering of Brad Pitt’s face, the sepia-toned nostalgia of New Orleans, and the dim, gas-lit interiors of the 1920s. Specific to your query, "HDRi" (High Dynamic Range