User Manual

Hue vs. Lum
The Hue vs. Lum curve lets you increase or decrease the lightness of elements of
specific colors.
Darkening the woman’s jacket using the Hue vs. Lum curve; Left–original image, Right–altered image
This is a tricky curve to use with highly compressed footage, as it can quickly reveal artifacts in
the image if you aren’t careful. However, if you’re working with very high-quality footage, this
can be a great tool to darken specific hues to add richness and depth, or to lighten colorful
elements to which you want to draw attention.
Lum vs. Sat
The Lum vs. Sat curve is similar to the Custom curves in that alterations to the saturation of an
image are based on user-definable ranges of image tonality, rather than hue. In the following
example, the Lum vs. Sat curve is being used to decrease selectively the saturation of
everything falling into the highlights and shadows of the image, while increasing the saturation
of everything within the midtones.
In the following example, a vividly saturated treatment results in shadows that seem artificially
colorful. Using the Lum vs. Sat curve, it’s easy to gradually desaturate everything below a
certain range, with a nice smooth falloff.
This is an outstanding curve to use for creative effect, for example, slightly boosting saturation
within the midtones while reducing saturation in the shadows to increase the depth of the
darkest portions of the image. It’s also a great curve to use to solve QC violations. For example,
if you have illegal saturation in the highlights of an image, you can use the Lum vs. Sat curve
cleanly and smoothly to lower the specific values that are causing problems.
Chapter – 118 Curves 2690