Color correction and adjustment

Jeff Sengstack provides an overview of color correction and enhancement on the Pro Video Coalition website.

This blog post contains a compilation of color correction and color grading tutorials from Robbie Carman, Jeff Sengstack, Jarle Leirpoll, Karl Soule and Andrew Devis.

For a video and print tutorial about correcting color, see the Adobe website.

Karl Soule on Three-Way Color Corrector and color correction in this video on AdobeTV.

Maxim Jago explains how to correct color and exposure in a video from “Adobe Premiere Pro CS5: Learn By Video” from Video2Brain.

Steve Hoeg, software engineer for Adobe Premiere Pro, explains how colors are processed within Premiere Pro, including how and when colors are converted between RGB and YUV color models in this forum post.

Jeff Sengstack explains the Premiere Pro, color correction workflow in this movie from his lynda.com tutorial -- Premiere Pro: Color Correction and Enhancement.

Here's a link to a tutorial on www.premierepro.net that shows advanced color grading in Premiere Pro CS5.5.

Editor and colorist, Robbie Carman, explains color correction and grading techniques for Premiere Pro in this workshop presented by Adobe.

In video, color correction encompasses adjusting both the hue (color or chroma) and luminance (brightness and contrast) in an image. Adjusting the color and luminance in video clips can create a mood, eliminate a color cast in a clip, correct video that’s too dark or too light, or set the levels to meet broadcast requirements or to match color from scene to scene. Effects can also adjust the color and luminance to emphasize or de-emphasize a detail in a clip.

You can find the color- and luminance-adjusting effects in the Color Correction bin inside the Video Effects bin. Although other effects also adjust color and luminance, the Color Correction effects are designed for making very fine color and luminance corrections.

You apply the Color Correction effects to a clip the same way you apply all Standard effects. The effect properties are adjusted in the Effect Controls panel. The Color Correction effects and other color effects are clip-based. However, you can apply them to multiple clips by nesting sequences. For information about nesting sequences, see Nest sequences.

Jeff Sengstack explains how to analyze clips for tonality issues in this lynda.com video from his tutorial -- Premiere Pro: Color Correction and Enhancement.

When correcting color, it’s useful to use the Vectorscope or waveform scopes (YC Waveform, RGB Parade, and YCbCr Parade) to help you analyze the chroma and luminance in a clip. You can view a scope in a separate Reference Monitor that’s ganged to the Program Monitor so that you can check your video levels as you make adjustments.

For information about scopes, see Waveform monitors and vectorscope.

The following is a suggested procedure for setting up your color correction workspace. It’s meant only as a starting point so you can configure the workspace to suit your style of working.

The following procedure is a general overview of applying the Color Correction effects. See the following sections in this chapter for making adjustments using the specific controls.

The Fast Color Corrector and the Three-Way Color Corrector effects have controls to quickly balance colors so the white, grays, and black are neutral. The adjustment that neutralizes the color cast in a sampled area is applied to the entire image. This can remove the color cast in all colors. For example, if an image has an undesirable bluish cast, when you sample an area that should be white, the White Balance control adds yellow to neutralize the bluish cast. This yellow adjustment is added to all the colors in the scene, which should remove the color cast in the entire scene.

The Fast Color Corrector and the Three-Way Color Corrector effects have automatic controls for making quick adjustments to the luminance in a clip. For a video on correcting color and luminance with the Fast Color Corrector, see the Adobe website.

The Fast Color Corrector and the Three-way Color Corrector effects offer Hue Balance and Angle color wheels and a Saturation control for balancing color in your video. Color balance is just what its name implies, balancing the red, green, and blue components to produce the desired color of white and neutral grays in the image. Depending on the desired effect, you may not want the color balance in a clip to be completely neutral. Perhaps you want an intimate family scene to have a warm (reddish) color cast or maybe the scene in your crime documentary requires a cool (bluish) color cast.

The color wheel adjustments offer the following adjustments:

The Saturation slider controls the color saturation in the video. Moving the slider to 0 desaturates the image so only the luminance values show (an image made up of white, grays, and black). Moving the slider to the right increases the saturation.

Although the following procedure uses the color wheel adjustments. The same adjustments can be made by entering numeric values or using the slider controls in the Fast Color Corrector and Three-way Color Corrector effects.

The curves adjustment of the Luma Curve and the RGB Curves effects, like the Levels sliders in the Fast Color Corrector and the Three-way Color Corrector effects, let you adjust the entire tonal range or just a selected range of colors in a video clip. But unlike Levels, which has only three adjustments (black level, gray level, and white level), the Luma Curve and RGB Curves let you adjust up to 16 different points throughout an image’s tonal range (from shadows to highlights).

The Fast Color Corrector and the Three-way Color Corrector effects have Input Levels and Output Levels controls to adjust the luminance in a clip. The controls are similar to the ones in Photoshop’s Levels dialog box. In the Fast Color Corrector effect, control settings are applied to all three color channels in a clip. The Three-way Color Corrector effect lets you apply the levels adjustments to the entire tonal range in the clip, a specific tonal range, or specific range of colors.

You can use the Adobe Color Picker to set target colors in some color and tonal adjustment effects. Clicking a color swatch in an effect’s controls opens the Adobe Color Picker.

In the Adobe Color Picker, you can select colors based on the HSB (hue, saturation, brightness), RGB (red, green, blue), HSL (hue, saturation, luminance), or YUV (luminance and color difference channels) color models, or you can specify a color based on its hexadecimal values. Selecting the Only Web Colors option configures the Adobe Color Picker so that you can choose only from wheelbase colors. The color field in the Adobe Color Picker can display color components in HSB, RGB, HSL, or YUV color mode.

The Luma Corrector, RGB Color Corrector, and Three-way Color Corrector effects let you define the tonal ranges for the shadows, midtones, and highlights so you can apply a color correction to a specific tonal range in an image. When used along with the Secondary Color Correction controls, defining a tonal range can help you apply adjustments to very specific elements in the image.

The Secondary Color Correction property specifies the color range to be corrected by an effect. You can define the color by hue, saturation, and luminance. The Secondary Color Correction property is available for the following effects: Luma Corrector, Luma Curve, RGB Color Corrector, RGB Curves, and Three-way Color Corrector.

By specifying a color or range of colors using the Secondary Color Correction, you are isolating a color correction effect to specific areas of an image. This is similar to making a selection or masking an image in Photoshop. For example, you define a range of colors that selects only a blue shirt in an image. You can then change the color of the shirt without affecting any other areas of the image.

The Color Pass effect lets you isolate a single color or a range of colors. Adjustments are made in a dialog box showing the Clip Sample and Output Sample. You can also adjust the Color Pass effect properties in the Effect Controls panel.

You can control the fine details of blurring, embossing, sharpening, and other effects by applying the Convolution Kernel effect or one of the convolution presets based on it. Convolution Kernel, and the presets based on it, overlays a matrix of numbers onto a matrix of pixels. You can set the values for each cell in the matrix using sliders in the Effect Controls panel, and you can use keyframes to change these values over time. To achieve a desired effect, it is often easier to apply one of the convolution presets and to modify it, than to apply and modify the Convolution Kernel effect itself.

You can use up to five lights to introduce creative effects. You can control such lighting properties as lighting type, direction, intensity, color, lighting center, and lighting spread. There is also a Bump Layer control for using textures or patterns from other footage to produce special effects such as a 3D-like surface effect. For a video tutorial about using Lighting Effects and the Basic 3D effect, see Creating A Title On A Reflective Surface by Jeff Schell on his Digital Media Net blog.

You can directly manipulate the Lighting Effects properties in the Program Monitor. Click the Transform icon next to Lighting Effects in the Effect Controls panel to display the adjustment handles and Center circle.

A bump layer in the Lighting Effects lets you use the pattern or texture from a clip to control how light reflects off an image. Using a clip with textures like paper or water can create a 3D-like lighting effect.