Work with a Colorist
Technical requirements for color correction materials
Preparing a project for color correction:
- Combine editing into a single video track;
- Split the Nest/Compound Clip and Multicam;
- Remove all audio tracks;
- Check whether Full/Video Levels are correct when transcode is in codecs. Video Levels are preferable
_fl_ - Full Levels _vl_ - Video Levels
If it is not possible to transfer editing with one track, then several EDLs should be made. One EDL for each Video Track/Camera
List of necessary materials:
- DRT (Davinci Resolve Timeline)
The name format <project_name>_vXX.drt
<Project_name> — all symbols in the lowercase, only Latin characters, no special symbols or spaces
vXX (versionXX) — a version of editing - XML/AAF
The name format <project_name>_vXX.xml
<Project_name> - all symbols in the lowercase, only Latin characters, no special symbols or spaces
vXX (versionXX) - a version of editing - EDL
A separate file for each video track
Turn on Video levels, Original Video file name, and transitions
The name format <project_name>_vXX_lXX.edl <Project_name> - all symbols in the lowercase, only Latin characters, no special symbols or spaces.
vXX (versionXX) - a version of editing
lXX (layerXX) - a number of a layer of editing
Layers should be numbered bottom up
For example, yourmovie_v01_l01.edl - corresponds to the first version of the first (lower or main) layer
- Reference Clip
QT MOV ProRes 422 (proxy) / DNxHR LB 422
The desired frame size is 1920 x 1080, square pixels without margins.
There should be a source name, source time-code, and record time-code on an image - Work Files / RAW
In the case of using sources from digital cameras, only the duplicates that are included in editing should be selected and sent for assembling.
The structure should be as simple as possible and it should look typical for the camera (no folder names with spaces and non-Latin characters; keeping a structure typical for a particular format).
ProRes RAW must be transcoded to V-LOG and ProRes/DNxHR Codecs. In addition, Full or Video Levels must be specified.
! Davinci Resolve cannot work with ProRes RAW.
CG Render Passes are output in 32-bit codecs.
VFX Alpha channels can be output in TIFF/PNG formats.
- Codecs:
ProRes 4444 XQ / DNxHR 444 - these codecs contain little compression and don't overload a Work Station but they can have file sizes larger than some RAW files by the Size - Depth Info ratio.
12-bit is the maximum that is supported
DPX - this codec is output by sequencing and has 10-16-bit. It can be output without compression and the size of a file may be too big. Usually, it is used for archives and for Film Scans.
EXR - this codec is output by sequencing. It has 16-32-bit and supports multichannel. Usually, it is used in CG. When using 32-bit, it supports color spaces with Linear Gamma.
TIFF / PNG - these codecs are most often used to output Alpha channels in 8 or 16-bit.
Please be sure to check all materials. For example, EDL and AAF/XML can be imported back to the project to check the possibility of assembling, checking Edit Transitions, etc. for the correctness of prepared EDL and AAF/XML. If you have Retimes or Resizes, please write a note with a detailed description of the effect to simplify the process of assembling your project.
Also, feel free to ask questions about Production Pipeline and Colorist Workflow. It is important to be on the same page at the beginning of the work in order to run your project more effectively and efficiently.
Post-Production Pipeline
I work in a Scene-Referred Workflow.
LogC3 is the main color space. Below is an example illustration of the 32 Bit Digital Post-Production Pipeline in a simplified form. The order of actions may vary but the connection between individual production nodes does not have much variation or opportunity to be different.
I have mapped the recommended ACES process. I prefer LogC3/Linear over ACEScct because it allows me to offer more creative solutions. But I use ACES to convert Camera Log Files and Renders Passes EXR.
You have to open the image in a new browser tab to view it in full size.
If it is not possible or not necessary to follow the 32-bit Pipeline in your project, you can follow the Base 12-bit Pipeline. In this case, Camera Log and 12-bit codecs/RAW are used.
To reduce the overall size of your project, you can use File > Media Management tool inside Davinci Resolve before sending it for color correction.
This tool allows you to trim RAW files by mountings within Timelines or an Entire Project. Basic RAW files are supported: ARRIRAW, RED, Blackmagic.
You can see other supported files on the official Blackmagic Davinci Resolve website. There is also an official PDF file about supported Formats/Codecs - Link
Production ODT-3D LUT
Custom ODT/3D LUTs are a good help in many stages of video content production. Basic ODT (Output Device Transform) or standard 3D LUTs from camera manufacturers usually have poor quality or a flat-like look.
So I decided to learn to create my own ODTs and 3D LUTs for my projects to improve the quality of my work and expand my creativity. It also extends the ability to copy Film Looks by copying a cast of Primaries and other characteristics of a film image and allowing you to see a similar image on a Digital Camera.
It is very important to build ODT/3D LUTs correctly without disturbing the gradation of colors and to understand the gray point and the contrast of the camera.
I tried to build my ODT using a mix of subtractive Kodak Print Film 2383 Primaries and ACES 709 ODT Contrast Curve and Saturation Mapping and some other nuances I prefer.
Below I will give some examples of good and bad ODTs, as well as a comparison of my ODT and ARRI Classic 3D LUT. When gradients are distorted on the 3D LUT Stress Test and produce artifacts, it means that the same thing will happen in a real scene. For example, in a scene with several very saturated light sources.
Let's start with the Stress Test LUT of the image, correctly converted to LogC, and use different ODT/3D LUTs for comparison. I’ll make my version via Davinci Resolve Nodes, which can be converted to 3D LUT. I will also add some effects like Halation, Bloom, Grain to show that everything works correctly in Scene-Referred Workflow.
Basic Image 3D LUT Stress Test
ARRI Classic 3D LUT. You can see that there are sharp borders in the area of Blue\Cyan and Magenta.
LogC 3D LUT from Web. There is a lot of distortion that may not be very visible in a neutral image, but in the case of complex scenes, these artifacts will make themselves noticeable.
Custom Davinci Resolve ODT + Film Halation, Bloom, Grain.
ARRI Classic 3D LUT. You can see a sharp transition between the upper light source and the background.
Custom Davinci Resolve ODT + Film Halation, Bloom, Grain.
Custom Davinci Resolve ODT + Film Halation, Bloom, Grain.
For a correct Film Emulation with Film Scan in Digital Camera ODT it is necessary to shoot several images on two cameras: on a film camera and on the one where you want to transfer. You should correctly develop a film image in Cineon Log, DPX. Images themselves should have a simulation of bright colored light sources, some Color Checkers, and native White Balance 5600k light directed at two people with dark and light skin in the frame.
Some test scenes are well shown in this video from Netflix - Link to Video.
It is important to understand that correct Negative/Print Film Emulation requires a camera with at least a 12+ bit Sensor.
Adobe 8 Bit ProRes Fix
By default, Adobe programs output 8-bit ProRes 4444, not the 12-bit we need. There is also a distortion of color. If Transcode was made under the Mac operating system, it is important that the Enable Display Color Management mode is set and the correct mode in the Mac system - Rec 709 - is selected. For more information, see the Adobe site - Link. For Windows users, this action is not required.
To solve the problem with 8-bit ProRes 4444, you need to enable these options.
And it is also important to leave these options by default.
Certification
My reference display is the LG OLED C1, calibrated by ICG Calibration Specialist Alex Prohorushkin (Independent Colorists Guild and Professional Calibration Service). My Work Station can handle 6k Source Footage + Film Emulation and 12K Source Footage with Standart Workflow.
