🎬Post Production FX Editing Unit 8 – Color Correction and Grading

What's Color Correction & Grading?

• Color correction involves adjusting the color, contrast, and exposure of video footage to achieve a natural, balanced look that matches the intended aesthetic
• Aims to fix issues like color casts, over/underexposure, and inconsistencies between shots
• Color grading builds upon correction by creatively manipulating the colors to establish a specific visual style or mood
  • Can involve applying stylized looks (film emulation) or enhancing certain colors to evoke emotions
• Both processes are crucial for ensuring footage looks its best and maintains continuity throughout a project
• Typically done in post-production using specialized software (DaVinci Resolve, Adobe Premiere Pro)
• Requires a combination of technical skill and artistic vision to effectively enhance the storytelling and visual impact of a video

Key Tools & Software

• Non-Linear Editing (NLE) systems like Adobe Premiere Pro, Final Cut Pro, and Avid Media Composer often include built-in color correction and grading tools
• Dedicated color grading software such as DaVinci Resolve and FilmLight Baselight offer more advanced features and control
• Color wheels and curves are essential tools for adjusting hue, saturation, and luminance
  • Color wheels divided into shadows, midtones, and highlights for targeted adjustments
  • Curves allow for precise control over specific color channels and tonal ranges
• Vectorscopes and waveforms provide visual feedback for monitoring color balance and exposure
• LUTs (Look-Up Tables) are preset color transformations that can be applied to footage for quick stylization or color space conversion
• Control surfaces (panels) with physical knobs and buttons offer tactile control for fine-tuning adjustments

Color Theory Basics

• Understanding color theory is essential for effective color correction and grading
• The color wheel organizes colors based on their relationships and can guide color harmony decisions
  • Primary colors: red, blue, yellow
  • Secondary colors: green, orange, purple (created by mixing primary colors)
  • Tertiary colors: result from mixing a primary and adjacent secondary color
• Complementary colors are opposite each other on the color wheel (red/green, blue/orange, yellow/purple) and create strong contrast when used together
• Analogous colors are adjacent on the color wheel and create harmonious, cohesive looks
• Hue refers to the actual color (red, green, blue), while saturation is the intensity or purity of the color
• Luminance (brightness) is the perceived lightness or darkness of a color
• The HSL (Hue, Saturation, Luminance) color model is commonly used in color grading software

Primary Correction Techniques

• Primary correction focuses on global adjustments that affect the entire image
• White balancing ensures neutral colors appear accurate by adjusting the color temperature and tint
  • Can be done using white balance presets (daylight, tungsten) or manually using color wheels
• Exposure correction involves adjusting the overall brightness and contrast of the image
  • Achieved using the lift (shadows), gamma (midtones), and gain (highlights) controls
• Balancing color channels (red, green, blue) helps remove color casts and achieve a neutral starting point
• Adjusting saturation can make colors more vivid or subdued depending on the desired look
• Contrast adjustments control the difference between the darkest and lightest parts of the image
  • Increasing contrast can add depth and pop, while decreasing it can create a softer, flatter look
• Clarity and sharpness tools can enhance texture and detail, but should be used sparingly to avoid an artificial look

Secondary Color Adjustments

• Secondary color correction targets specific colors, objects, or regions within the image
• Qualifiers (HSL, RGB) allow for isolating and adjusting specific color ranges
  • Can be used to selectively adjust skin tones, skies, foliage, or other elements
• Power windows are shape-based masks (circular, linear, polygonal) used to define regions for localized adjustments
  • Useful for directing the viewer's attention or balancing exposure in different areas of the frame
• Tracking can be applied to power windows to make them follow moving objects throughout a shot
• Blending modes (overlay, soft light, multiply) can be used to combine secondary adjustments with the original image in creative ways
• Keying techniques (chroma key, luma key) can isolate subjects based on color or brightness for targeted corrections
• Secondary adjustments are often used to refine the look after primary corrections have been made

Creating Specific Looks

• Color grading allows for creating distinct visual styles that enhance the mood, atmosphere, or genre of a video
• Emulating film stocks (Kodak, Fuji) can give footage a cinematic look with characteristic color and contrast profiles
  • Achieved using film emulation LUTs or manual adjustments to color balance, saturation, and contrast
• Bleach bypass is a high-contrast, desaturated look that can add grit and intensity to a scene
• Teal and orange is a popular complementary color scheme that emphasizes skin tones and creates a Hollywood blockbuster aesthetic
• Day for night involves color grading daytime footage to appear as if it were shot at night
  • Typically involves cooling the color temperature, increasing contrast, and adding blue tints to shadows
• Sepia toning creates a warm, vintage look by adding brown and yellow hues to the image
• Black and white grading can be used for stylistic or historical effect, with control over the luminance of individual color channels
• Split toning allows for applying different color tints to the shadows and highlights for a stylized, duotone look

Color Grading Workflows

• Color grading workflows can vary depending on the project requirements and personal preferences
• Start with primary corrections to balance the footage and create a neutral foundation before moving on to creative grading
• Use reference stills or color charts to ensure consistency and accuracy across shots and scenes
• Work with a calibrated monitor and controlled lighting environment to ensure accurate color representation
• Use the scopes (waveform, vectorscope, histogram) to objectively assess exposure, color balance, and saturation levels
• Apply LUTs or pre-built looks as a starting point, then refine with manual adjustments to suit the specific footage
• Use node-based workflows to layer and organize corrections, allowing for non-destructive adjustments and easy tweaking
  • Each node represents a specific correction or effect, with the ability to selectively apply them to different parts of the image
• Render out multiple versions (passes) of the graded footage to provide flexibility in the final edit
• Collaborate with the director, cinematographer, and other stakeholders to ensure the grade aligns with the creative vision of the project

Troubleshooting Common Issues

• Color banding: Occurs when there are visible steps or bands in gradients due to compression or limited bit depth
  • Can be mitigated by adding noise or dithering to the image, or by using higher bit depth formats
• Clipping: When highlights or shadows lose detail due to being pushed too far in the grading process
  • Avoid clipping by monitoring the waveform and making adjustments to keep values within the acceptable range
• Inconsistency between shots: Can occur due to changes in lighting, camera settings, or grading decisions
  • Use reference stills, color charts, and the scopes to match shots and maintain consistency throughout the project
• Oversaturation: When colors become too intense or unrealistic due to aggressive grading
  • Monitor the vectorscope and make adjustments to keep saturation levels within the broadcast-safe range
• Noise and grain: Can become more apparent or amplified during the grading process, especially in underexposed or heavily manipulated footage
  • Use noise reduction tools sparingly to avoid loss of detail, or embrace the grain as a stylistic choice
• Artifacts and compression issues: Can arise from working with heavily compressed or low-quality source footage
  • Use the highest quality source material available and be mindful of the limitations of the footage when grading
• Monitor calibration: Inconsistencies in monitor calibration can lead to inaccurate color representation and grading decisions
  • Regularly calibrate monitors using hardware calibration tools and maintain a consistent viewing environment