Livegrade implements the ACES color pipeline including IDT transforms, working color spaces such as ACEScct and ACEScc, LMT, RRT and ODT transforms to be used on camera live signals and still images (e.g. for reference) on the film set.
The ultimate goal is to create the same visual result on an on-set monitor (showing the ACES-processed live signal of a camera) compared to the monitors in a color corrector (showing the ACES-processed recorded source clips from the camera). Livegrade also offers export of ACES-based looks in the ACES Metadata File format (for ACES version 1.2 and newer).
The following diagram shows an example ACES pipeline as implemented in Livegrade.
Step-by-Step: How to Configure Livegrade to Start Using ACES
- Open the Livegrade Pro or Livegrade Studio application.
- Go to the the “ACES” section in the application preferences (Main Menu: “Livegrade > Preferences…”) to set the ACES version for new looks and download desired ACES versions.
- Choose the grading mode “ACES CDL” or “ACES CDL Advanced” by selecting it from the dropdown positioned on top of the grading interface next to the label “Look”.
- Select the intended input and output transform for your setup depending on camera input and display output. That can be done with of the IDT and RRT+ODT nodes of the grade.
- You will now be able to preview and manipulate the image signal in the selected ACES working space (ACEScc or ACEScct).
ACES grading modes
Livegrade implements this pipeline in the ACES (Academy Color Encoding System) grading modes. You can see the nodes and controls of the “ACES CDL” grading mode in the screenshot below. On every interaction with the color controls of the ACES grading mode (e.g. change of IDT, modify of ASC-CDL) all transforms are baked together automatically and sent to an attached LUT box.
Livegrade also offers the “ACES CDL Advanced” grading mode. This grading mode lets you add multiple grading nodes between the IDT and ODT and LMTs for advanced workflows.
You can take a look at how to use the advanced modes in the article Grading Modes in Livegrade.
The CDL controls behave the same way as in the CDL Grade mode and can also be exported as usual from a saved grade. ACES grades can also be exported as 3D LUTs, including the CDL values, IDT and ODT.
For more information about how to export LUTs: Exporting Grades
From ACES version 1.3 you can enable the “Reference Gamut Compress” parameter within the IDT node of ACES grading modes. The ACES Reference Gamut Compression achieves better accuracy with extreme color ranges and replaces the LMT “Blue Light Artifact Fix” that was widely used in previous ACES versions.
The metadata fields “ACES Input Transform”, “ACES Input TransformID”, “ACES Output Transform”, “ACES Output TransformID and “Reference Gamut Compress” allow inspecting ACES look metadata in the shot library and communicating relevant info in PDF reports.
Look Modification Transforms (LMTs)
You can add a “LMT” node in Livegrade (in the ACES CDL Advanced grading mode) that supports the official, predefined LMT transforms shipping with the respective ACES version as well as custom 3D LUTs.
Note: LMTs are specified by the ACES specification as a transform from and to ACES AP-0 (the linear ACES color space). Consequently, loaded LUTs in the LMT node will always be applied in ACES AP-0. For this reason the LMT node only accepts LUTs in the Common LUT Format (CLF) matching the ACES specification. If you need to load a 3D LUT (e.g., in a typical grading working color space such as ACEScct), you can add a 3D LUT node and load any compatible 3D LUT format without limitation. LUTs in the 3D LUT node will be applied in the working colorspace (ACEScct/ACEScc).
Managing ACES Versions
Livegrade supports multiple versions of ACES, ranging from 0.7.1, 1.0, to the latest ACES version 1.3. For compatibility with the post production workflow please choose the right ACES version, as the transforms can be slightly different in different versions, and newer version usually include more and more recent input (IDT) and output (ODT) transforms, including RRT+ODT transforms for HDR in ACES version 1.1 or higher.
Note: Transforms for ACES version 1.2 can be downloaded from Livegrade v5.1.3 or higher, transforms for ACES version 1.3 can be downloaded from Livegrade v6.0 or higher
In the Livegrade preferences you can manage and download the available ACES versions and transforms:
The dropdown lets you select the ACES version for new looks. Every new look will be initialized with the ACES version selected in the dropdown in the preferences.
Every look in the library made with an ACES grading mode has an associated ACES version (you can find that version in the “ACES Mode” column). Saving looks with different ACES versions to the library will make it easy to compare the look of different ACES versions effortlessly.
In the section “Available ACES Transforms” you can find the available ACES versions and its associated transforms. The icon in the status bar will either signalize an available set of transforms (green checkmark) or a set of transforms that can be downloaded from the servers (download icon with downwards arrow).
Click the button “Check for New Versions” at the bottom of the preferences window to see if new ACES versions are available to download from the Pomfort servers.
Exporting ACES-based Looks as AMF
Livegrade can export the current look of a slot or stored looks in the shot library as AMF files (ACES version 1.2 or higher). Currently, the export of AMF is limited to the ACES CDL grading mode. See Exporting Shot Information for more details on exporting shot and look metadata from Livegrade.
Devices and Utilization
With Livegrade the ACES grading mode can be used in different setups, e.g. with LUT-Boxes such as the Teradek COLR, FSI BoxIO or TV Logic’s IS-Mini or directly with a monitor such as the Flanders Scientific DM250 broadcast monitor, that has processing capabilities included.
To learn more about the hardware setup of Livegrade see the article about HD-SDI setup for Livegrade.
Please note that for ACES color pipelines a LUT device with a LUT size of 23 or 33 (or higher) is recommended. Otherwise the device might introduce interpolation problems such as bending or wrong levels in some areas of the visible color space.
Supported ACES IDT and ODT Transforms
Livegrade offers all officially (in the Academy’s repository) available IDT and ODT transforms, as well as a few custom transforms by Pomfort. Please take a look at the available transforms in Livegrade’s preferences in the “ACES” tab.
ACES landing page
See https://pomfort.com/workflow/aces/ for an overview of ACES related topics with Pomfort’s products.