User Guide - Color Scattering Wheels
Tint shadows and highlights with the Color Scattering Wheels
The tools in Color.io are fundamentally designed to allow for natural, film-like color processing. To get the most out of the color wheels in Color.io, it's important to understand that they emulate how light behaves in the physical world.
Light interacts with the objects in a scene and creates the colors and shades we perceive. In a natural environment, you might have a direct light source, like the sun (a scene illuminant or highlight), and an indirect source, like the sky or surrounding objects (which create an ambience color cast in the shadows). This indirect light source gives us the color we perceive in shadows, as it's often bounced (or scattered) light.
Think of it like this: when it's a clear day and the sun is shining, the highlights in the scene are a bright, warm light (coming directly from the sun), but the shadows aren't just darker versions of the same color. Instead, they have a cooler, bluish tint. This bluish tint is the result of light from the sun being scattered in the sky, then that scattered blue light is illuminating the shadow areas.
The scattering emulation wheels in Color.io are designed to mimic these natural lighting conditions. So you get separate control over the highlight colors (direct sunlight) and the shadow colors (scattered light).
Shadow Scattering
Use the shadow scattering wheel to add ambient color to the shadows of an image. Unlike traditional color wheels, scattering holds on to the naturally occurring shadow colors in an image longer and tints dark pixels in a way that is consistent with light behaviour in the physical world.
Highlight scattering works similarly although instead of protecting color purity, the algorithmic color model is optimized to prevent highlight spill over into the lower luminance range of the image which is typical of traditional lift gamma gain controls.
Highlight Scattering
Use the highlight scattering color wheel to tint the highlights of the image with a specific tone. The highlight scattering algorithm automatically protects color purity and is optimized to prevent highlight spill over into the lower luminance range of the image which is typical of traditional lift gamma gain controls.
Pro Tip: Use both wheels in combination to create powerful color contrasts and film tint emulations. Most motion picture film stocks have slightly cool shadows and slightly warm highlights: Try to move the shadow point to a cold hue and the highlight point in the opposite direction to tint highlights warm to enhance color contrast and create a cinematic color grade.
Why is there no midtone control?
Many color grading tools come with color wheels for shadows, midtones and highlights (often called Lift, Gamma, Gain). Since Color.io emulates the way light behaves in the physical world, the color wheels in Color.io behave differently than traditional tools. In this color model, midtones are really just a mixture of your highlights and shadows which is why there is no separate color wheel for them. Midtones are regions that are partially lit, receiving both direct and scattered light. Thus, their color is influenced by both the highlight color and the shadow color. Separate midtone controls could easily break the continuity of this emulation. Instead, midtones are automatically influenced by the adjustments you make to the highlights and shadows.
To make broad, sweeping adjustments to the color distribution of the entire image, the Spectral Balance control is your best choice. Spectral Balance introduces natural color shifts across the entire tonal range. When you combine Spectral Balance with shadow and highlight scattering, you can get separate tones for shadows, midtones and highlights, but without breaking the color gradation or creating unnatural results. This is what Color.io is designed for.
Shortcut: Double click a control point to snap it back to its origin in the center of the color wheel. To reset both color wheels click the reset button on the top right of the panel.
With Color.io you can edit images and build 3D LUTs with a powerful online raw developer and analog film look designer for photographers and filmmakers. Craft stunning film color in record time that works for any camera, in any software and on any device, directly in your browser.
