For nearly 20 years, cinema production and post-production has been based upon the conceptual model of film acquisition: Even if digitally acquired, imagery was typically processed using the Cineon/DPX model– technically, Cineon Printing Density (CPD) coding. That coding incorporates the technical parameters of film; in particular, the S-shaped tone response and the colour crosstalk of film are built-into the image encoding. Because CGI and VFX computations are best performed in linear-light, the CPD scheme has made CGI and VFX difficult.