HDR Requires Larger LUTs

JD Vandenberg, Director of Post Production @ The Walt Disney Studios, found that 33X33X33 LUTs developed for SDR are too small for working with HDR footage. So what’s the minimum size 3D LUT required to minimize visual artifacts in PQ HDR content? Vandenberg’s study concluded that 10-bit material necessitates the use of LUTs that are 50% larger than 12-bit material – and darker, more saturated images call for even larger LUTs. 12-bit requires the use of 3D LUTs larger than 55X55X55 when using tetrahedral interpolation.