Other Types of HSL Adjustments
There are other tools available in different grading applications for making similar types of targeted adjustments based on specific ranges of hue. Although the techniques found throughout this book focus on the use of Hue curves where appropriate, it's useful to know that the following styles of correction may be substituted should you feel there is an advantage to doing so.
Before HSL Qualification and hue curves, there were vectors, a means of isolating a wedge of color as represented by its distribution on a vectorscope for isolated adjustment. In 1982, VTA Technologies (the predecessor to DaVinci) introduced The Wiz, a telecine controller and color corrector built upon an Apple II computer, which featured 10-vector secondary correction. Later in 1989, the renamed DaVinci Systems introduced the more accurate sub-degree Kilovector system to the Renaissance grading system.
Vector-style secondary correction is still in use and is now available in many different grading applications. Assimilate Scratch has a Vector interface, providing six customizable color ranges that you can use to shift the hue, saturation, and lightness of isolated ranges of color. Other applications with Vector-style adjustments include FilmLight Baselight and Quantel Pablo.
In the Assimilate Scratch interface, the Centre parameter specifies the angle of hue that's being isolated for adjustment, while the Width parameter specifies how much of a range of values to the left and right of the center hue to include within the adjustment (Figure 4.63).
Figure 4.63 The Vector UI in Assimilate Scratch.
The six color pots of the UI show the default colors that can be immediately adjusted, namely the primary and secondary colors of the RGB color space. Clicking a pot selects that range of hues for adjustment, and adjustment of the Hue Shift, Saturation, and Lightness parameters allows them to be modified.
Other interesting implementations of vector controls include the following:
- Baselight has a Six Vector grade, using a UI similar to that of the Hue Angle keyer, that lets you choose one of six customizable hue ranges to adjust using either knobs on the control surface or sliders within the onscreen UI.
- Quantel's Pablo, iQ, and eQ systems have an interface called Revolver (Figure 4.64), which provides six customizable controls for altering color ranges. However, the adjustments are made using "color warping" algorithms that allow for a different quality of adjustment.
Figure 4.64 The Revolver UI in Quantel Pablo, iQ, and eQ.
Grading with Hue Shift in FilmLight Baselight
FilmLight Baselight has another style of hue adjustment called the Hue Shift grade. Applying this adjustment opens a UI consisting of vertical sliders that correspond to each of the primary and secondary hues of the RGB color space.
To make an alteration to the image, simply manipulate the slider that corresponds to the hue you want to adjust. Two sets of sliders let you individually adjust the hue and saturation of each color range (Figure 4.65).
Figure 4.65 The Hue Shift UI in FilmLight Baselight.