HDR grading revolutionizes video production by expanding luminance and color ranges. It allows for greater contrast, more vibrant colors, and increased bit depth, resulting in smoother gradients and more precise color representation. This technique enhances realism and viewer immersion.

Preparing for HDR grading involves shooting in RAW or log formats, proper exposure techniques, and color space selection. Specialized software and tools are used to manipulate extended luminance and color ranges. Delivery requires mastering content for various HDR standards and creating SDR versions for compatibility.

HDR Grading Principles and Advantages

Expanded Dynamic Range and Color Capabilities

• High Dynamic Range (HDR) grading expands luminance and color range in video content allowing greater contrast and more vibrant colors than Standard Dynamic Range (SDR)
• Supports wider color gamut using Rec. 2020 color space encompassing larger portion of visible colors compared to Rec. 709
• Increased bit depth (10-bit or 12-bit) allows smoother gradients and more precise color representation reducing banding artifacts
• Enables more accurate representation of real-world lighting conditions enhancing viewer's sense of realism and immersion (sunsets, candlelight)
• Preserves more detail in highlights and shadows allowing greater creative control in post-production and more impactful visual experience for viewers
  • Example: Retaining cloud details in bright sky while maintaining shadow information in darker areas of the scene

HDR Standards and Implementation

• Various HDR standards exist with specific capabilities and implementation methods:
  • HDR10: Open standard supporting up to 1000 nits peak brightness
  • HDR10+: Adds dynamic metadata for scene-by-scene optimization
  • Dolby Vision: Proprietary format supporting up to 10,000 nits peak brightness
  • Hybrid Log-Gamma (HLG): Backwards-compatible with SDR displays, commonly used in broadcast
• Each standard requires different grading approaches and delivery specifications
  • Example: Dolby Vision requires creating both HDR and SDR versions simultaneously using special tools

Preparing Footage for HDR Grading

Capture and Exposure Techniques

• Shoot in RAW or log formats capturing widest possible dynamic range and preserving maximum flexibility for HDR grading
• Properly expose footage during production avoiding clipping in highlights and crushing in shadows to maintain detail across entire luminance range
  • Example: Using false color tools to ensure proper exposure of skin tones while retaining highlight detail in bright windows
• Analyze scopes and waveforms ensuring footage's luminance and color information fall within desired HDR range typically up to 10,000 nits for peak brightness
• Apply Input Device Transforms (IDTs) when working in ACES to ensure proper color management throughout HDR workflow

Color Space and Calibration

• Select appropriate color spaces for HDR workflows supporting high bit depths and wide color gamuts (ACES, OpenEXR)
• Calibrate monitors and viewing environments ensuring accurate color representation and proper assessment of HDR imagery throughout grading process
  • Example: Using a colorimeter to calibrate HDR monitor to specific peak brightness and color gamut standards
• Convert footage to appropriate working color space supporting HDR (ACEScct, ACEScc) before beginning grading process
• Apply Output Device Transforms (ODTs) when working in ACES to ensure proper color management for specific HDR output formats

Expanding Dynamic Range with HDR Tools

HDR-Specific Software and Techniques

• Employ HDR-capable color grading software offering specialized tools for manipulating extended luminance and color ranges (DaVinci Resolve, Baselight, Nucoda)
• Utilize HDR-specific color wheels and curves adjusting highlights, midtones, and shadows while maintaining proper balance across expanded dynamic range
• Apply HDR-optimized LUTs (Look-Up Tables) designed to take advantage of wider color gamut and increased luminance range
• Implement HDR-specific noise reduction techniques addressing potential noise issues in shadow areas becoming more visible with increased dynamic range
  • Example: Using temporal noise reduction to clean up shadow details without affecting highlight information

Advanced HDR Grading Techniques

• Employ selective color grading techniques isolating and enhancing specific luminance ranges or color regions within HDR image
  • Example: Using HDR-specific qualifiers to isolate and enhance specular highlights on water surfaces
• Utilize HDR-specific keying and masking tools creating precise selections for targeted adjustments in high-contrast areas
• Apply HDR-optimized sharpening and detail enhancement techniques taking advantage of increased resolution and clarity offered by HDR displays
  • Example: Using frequency separation techniques to enhance fine details without introducing artifacts in high-contrast edges

Delivering HDR Content for Various Formats

HDR Mastering and Versioning

• Master HDR content to appropriate peak brightness levels based on target display technology (1,000 nits for HDR10, up to 10,000 nits for Dolby Vision)
• Create multiple versions of HDR content accommodating different display capabilities and standards (HDR10, HDR10+, Dolby Vision, HLG)
• Implement dynamic metadata in HDR10+ and Dolby Vision workflows optimizing content appearance across various display devices with different capabilities
  • Example: Creating shot-by-shot brightness and color volume metadata in Dolby Vision to ensure optimal display on both high-end and entry-level HDR TVs

Delivery and Quality Control

• Utilize appropriate color management and EOTF (Electro-Optical Transfer Function) conversions when delivering HDR content for different platforms (streaming services, broadcast)
• Generate SDR versions of HDR content through tone-mapping techniques ensuring compatibility with legacy displays while preserving creative intent
• Apply appropriate compression techniques and codecs optimized for HDR content maintaining quality while managing file sizes for various delivery methods
  • Example: Using HEVC (H.265) codec with 10-bit color depth for efficient HDR streaming delivery
• Conduct quality control checks on multiple display types ensuring consistent appearance and proper HDR implementation across different viewing environments
  • Example: Verifying HDR content on consumer OLED, LED, and projection systems to ensure consistent viewer experience