Colorist Q&A: ACES, Dolby Vision, Archiving, Shadows, Broadcast Safe, Parallel Mixer, Multi-Camera Grading, and DaVinci Resolve Tools

Cullen Kelly

Color Management Using ACES in a Dolby Vision Project [02:55]

• Dolby Vision's core purpose is to derive multiple masters from a single HDR master, specifically creating SDR (Standard Dynamic Range) masters from an HDR (High Dynamic Range) source.
• The setup involves an ACES color management workflow:
  • Input Transform: Set to the camera's original color space (e.g., Arri Wide Gamut 3 Log C3).
  • Working Color Space: ACES CCT (ACEScc or ACEScct are common working spaces in ACES).
  • Output Transform: Initially target an HDR spec like P3D65 ST2084 1000 nit for the primary master.
• Enabling Dolby Vision in DaVinci Resolve involves:
  • Activating Dolby Vision in project color management settings.
  • Matching mastering display settings (color primaries, EOTF, peak luminance) with the output transform.
  • Dolby Vision stores instructions as a sidecar XML file that travels with the HDR master, informing compatible devices how to render the content optimally in either HDR or SDR.
• The advantage is streamlined delivery of multiple versions from one grade, but a potential downside is the shot-by-shot adjustment process, which some colorists find can lead to inconsistent results compared to a well-designed static transform.

Do You Use an MTF Curve When Building a Print Stock Look? [14:01]

• MTF (Modulation Transfer Function) describes a system's ability to reproduce contrast in fine details, applicable to lenses, displays, or film systems.
• The colorist currently does not use MTF curves in film stock emulation but is actively experimenting with it.
• He speculates whether MTF characteristics are fundamentally captured during acquisition, making significant post-capture manipulation difficult, or if current tools are simply inadequate.
• Texture is considered a crucial element for an imaging system's "magic" and can also contribute to an "icky" feel if not handled well.

Have You Tried the New Micro Panel? [16:15]

• The new DaVinci Resolve Micro Panel is highly regarded for its accessibility and tactile control, particularly for trackballs.
• It offers a lower entry point for colorists and those learning grading, making hands-on control more affordable.
• While not as premium feeling as the Mini or Advanced panels, it's a significant improvement over mouse-based grading.
• The new Micro Panel allows control over more interface elements, including Power Windows.

Do You Export EXRs When Saving a Project for Archive? [19:30]

• Archiving practices vary, often treated as a separate service from color grading.
• Short-term data retention: Projects are kept on servers for immediate use for about two weeks, then data for about six weeks, after which it's deleted unless a specific paid arrangement is in place.
• Long-term archival (for clients like streamers):
  • Involves generating "Graded Archival Master" (GAM) and "Non-Graded Archival Master" (NAM).
  • These are high-quality renders without the final output transform, allowing future flexibility for different outputs.
  • While EXRs can be part of archival, it's generally not the most common format for GAM/NAM, which are usually high-bit-depth video files.
• Personal archival: Project files are retained due to their lightweight nature and the amount of work they contain, allowing re-linking to original media if a client wants to revisit a grade later.

What Are the Best Practices for Maintaining Density in Your Shadows When You’re Going for a Very Crunchy Look? [23:16]

• Achieving a "crunchy" (high contrast) look while maintaining shadow density requires careful contrast shaping.
• Direct application of "contrast" can often crush shadows and lose detail.
• Recommended technique: Use custom curves with an anchor point at mid-gray.
  • Increase slope in the shadow regions to deepen them.
  • Slightly lift the black point to prevent complete clipping and preserve some detail.
• The goal is to create rich, pleasing contrast without aggressive clipping, ensuring shadows have depth but still hold information.
• This approach, when applied at a system level (e.g., through a project-wide look), ensures consistency across all shots rather than shot-by-shot adjustments.

Is Proper Color Management Enough to Make Your Piece Broadcast Safe? How Do You Avoid Any QC Errors? [30:15]

• Color management and broadcast safety: Proper color management largely helps avoid illegal values (values outside the display's allowed range).
• The colorist's perspective is that if an image looks good on a properly calibrated Rec. 709 master display and is within the display's capabilities, it should be considered acceptable.
• Broadcast safe issues are often divided into two categories:
  • Invisible clipping: Pixel values technically exceed the 0-1 range but are not visually apparent on a standard display. These are easy to fix with clamping tools and don't affect the creative intent.
  • Visible issues: If an image is "too red" or "too bright" within the display's visible range, this is a creative choice that should be respected if it looks good to the colorist and client.
• The colorist argues that broadcast standards should accommodate valid creative choices visible on a compliant display.

What Does a Parallel Mixer Node Do? How Can We Use It? [35:03]

• Layer Mixer: Stacks nodes like layers in Photoshop, with the lowest input having the highest visual priority. Adjustments in higher layers can completely obscure or interact with lower layers based on composite modes and key output gain.
• Parallel Mixer: Combines the effects of all input nodes with equal priority.
  • All adjustments from parallel nodes are incorporated simultaneously into the image, rather than stacking sequentially.
  • This means effects from different parallel nodes can blend or even cancel each other out.
  • Use cases:
    • Applying multiple localized adjustments (e.g., several power windows to different parts of an image) to the same base image and then combining their results. This is beneficial for elements that should not influence each other's input, like isolating different parts of a hamburger in a commercial shot.
    • Useful in template node trees where primary adjustments are combined with secondary corrections (qualifiers, windows) without hierarchical priority.

How Do You Handle Grading Big Projects with a Lot of Cameras with Different Color Spaces? [44:40]

• 1. Robust Color Management (Macro Level):

  • The first and most crucial step is to properly color manage all source footage.
  • Identify the original source of every shot and apply the appropriate input transform (IDT) to bring it into a common working color space (e.g., ACES CCT or DaVinci Wide Gamut Intermediate).
  • Confirm that the color management produces a "sane result"; if not, investigate and correct the color management setup rather than trying to "grade through" the problem.
  • Good color management establishes a level playing field, making subsequent matching easier.

• 2. The "Rug That Ties the Room Together" (Looks):

  • Apply a foundational "look" to the project. Looks not only provide a desired aesthetic but also help unify diverse footage, minimizing subtle mismatches in exposure, color balance, and frame content across different cameras.

• 3. Primary Adjustments (Greatest Gains for Least Effort):

  • After color management and a foundational look, focus on broad, simple adjustments:
    • Exposure and Contrast: These have a significantly greater impact on the viewer's experience than color. Ensure these are aligned across all shots first.
    • Color Balance: Once exposure and contrast are consistent, address color balance. Use clean methods like linear gain adjustments in a color-managed workflow.
  • This stage represents approximately 80% of the visual impact you can achieve in a project.

• 4. Diminishing Returns & Consistent Process:

  • Beyond primary adjustments, further localized or complex corrections (e.g., power windows, qualifiers, hue rotations) yield diminishing returns for the effort invested.
  • Maintain a consistent grading process: start macro (color management, look), then move to broad primary adjustments (exposure, contrast, balance), and finally to more localized, narrow adjustments.
  • This systematic approach helps navigate challenging projects and manage expectations about achievable improvements.

Is Any Look Possible with the Default Resolve Tools or Do You Need Extra LUTs, DCTLs, and Plug-ins? [57:00]

• DaVinci Resolve's Capabilities:

  • Yes, it is absolutely possible to achieve strong looks using only DaVinci Resolve's internal tools.
  • Resolve 19 has improved this with new tools like the Color Slice tool and the Film Look Creator.
  • However, achieving complex, bulletproof, and consistently pleasing looks across all shots and situations can be very time-consuming with only native tools.
  • It's also possible to make damaging adjustments with native tools if not used skillfully.

• Role of External Resources (LUTs, DCTLs, Plugins):

  • External LUTs (Look Up Tables), DCTLs (DaVinci Color Transform Language), and plugins offer significant advantages in terms of speed, efficiency, and specialized control.
  • They allow colorists to quickly apply sophisticated looks that would take prohibitive amounts of time to build from scratch with native tools, especially when targeting a specific aesthetic like film emulation.

• Color Grading vs. Look Development:

  • The core distinction lies between "color grading" (optimizing an image) and "look development" (creating a distinct visual style).
  • Resolve is a color grading platform, not specifically a look development creator.
  • Look development is a different skill set; a good colorist's skills don't automatically translate to being a good look development artist.
  • Using a LUT is being an "end user," while building a look from scratch in Resolve is being a "look dev artist," requiring a deeper and often different skill set.
  • The choice depends on time, desired control, and the colorist's skill in look development versus the efficiency offered by external tools.