Digital technology has recently become an alternative to film for the origination of motion pictures, for colour grading (in the form of the digital intermediate) and for display in exhibition. Each of these developments is advancing independent of the others, leading to hybrid film-digital workflows. However, film and electronic media capture and reproduce images in fundamentally different ways. Film uses subtractive colorants (CMY),but digital cinema uses additive primaries (RGB). Film is characterised using logarithms, but digital video and computer graphics is characterised using power functions. Film and digital cinema have different colour gamuts and are optimized for different contrast ratios. Digital Cinema Testbed at
the National FIlm Theatre,
South Bank,London,
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