The Digital Fact Book - Quantel

Grading (a.k.a. color timing)Grading is the process of adjusting the color of a clip to get the best out of the material orto match shots perhaps taken at different times or in different lighting conditions. In film,grading was traditionally done when going from internegative to print film by controlling theexposure of the film. In television it was traditionally done off the telecine for commercialsor tape-to-tape for longform programs. Either way, both processes were by their nature linear.GThe advent of non-linear grading systems (such as Quantel’s Pablo) has once again changedthe rules for color correction. While there is still a requirement for an initial technical scanfor film-originated material, from this point on, grading can – and often does – happen atmultiple stages in the post production process. It is now possible – and usually desirable– to color correct individual layers within composites (which may be shot under differentlighting conditions) to ensure that the result is harmonious within itself, and non-linear workingmeans that scene-to-scene comparisons and corrections can be made as the edit unfolds.This eases the final grading process when the finished work is reviewed interactively withthe director/client.Secondary color correction is aimed at controlling a particular color or a narrow rangeof colors – such as those on a car or product. Here typically the hue, gain and saturationcan be changed. There are also several methods available for defining the object, areaor ‘window’ of required color correction such as using wipe-pattern shapes, drawing anelectronic mask by hand or a combination of automatic and by-hand methods. Some ofthe most sophisticated tools are provided by media workstations such as Quantel’s eQ,iQ and Pablo.See also: Film scanner, Grading, Telecine94