This page provides information on the LUT Map.
VRayLUT is a V-Ray utility node that allows you to apply a look up table (a .cube file) to any texture for managing resulting colors.
In the example shown a LC3DL_Fuji3510_log2hd_ConstLmap.cube LUT file has been loaded to define the texture's look.
UI Path: ||Material Editor window|| > Material/Map Browser > Maps > V-Ray > VRayLut
Base map – A slot to load the map that you want the LUT to be applied to.
Browse – Click to load the look up table.
LUT file – Specifies the location of the look up table.
Convert to log space before applying LUT – Converts the Base map to a logarithmic color space before applying the look up table.