Creating a 3×3 Matrix for Camera Matching

Using mmColorTarget and DaVinci Resolve for Scene-Referred Film Profiling

If you’re diving into film profiling workflows using tools like mmColorTarget and DaVinci Resolve, the 3×3 Matrix Maker is a powerful utility that helps match your source camera image to a target film reference in a scene-referred color space with mathematical precision.

https://github.com/ctcwired/dctl-matrix-maker?tab=readme-ov-file

Step 1: Download and Install the Matrix Maker Script

First, download the ZIP archive that includes all required Python scripts (usually hosted on GitHub by the author or project). Once downloaded:

Extract the folder.
Open a terminal in that folder.
Install any Python dependencies if needed.
Just copy the commands from GitHub Link above

Tip: If you run into issues, just copy the error message into ChatGPT or another AI assistant — you’ll have it fixed in no time.

Step 2: Prepare Your Color Charts in EXR Format

Prepare your two comparison images:

Source Image: A render or still of the mmColorTarget captured with your camera (e.g. ARRI, RED, etc.).
Target Image: A reference mmColorTarget (e.g. a scan from a film stock or ideal target).

Color Space Matching Tips:

Bring both charts into the same working color space (e.g. ACEScg, Linear Rec.709, or any other linear space). Not necessary but can be a workflow improvement.
Matching grayscale tones beforehand can significantly improve results.
Once matched, render both images as EXR files:
- Name them exactly: source.exr and target.exr

Step 3: Run the 3×3 Matrix Maker Script

Open your terminal and navigate to the folder where the script is located:

ls     # List contents
cd     #directory where the folder is located
cd     matrix-folder-name     # Enter the folder where dctl-matrix-maker.py is located

Then run the script with your images:

python dctl-matrix-maker.py source.exr target.exr

The script will compare the two images patch by patch and automatically generate a DCTL file containing a 3×3 color transformation matrix.

Step 4: Apply the DCTL in DaVinci Resolve

Move the generated .dctl file into your DaVinci Resolve LUT or DCTL folder
Restart Resolve so it detects the new DCTL.
Inside your node tree, add a new DCTL node and select the matrix you just created.

Your source camera image will now closely match the film-scanned target in color.

Pro Tips for Better Results

Match the grayscale of your source and target images before running the matrix script. This ensures brightness alignment and improves the matrix accuracy.
Work in scene-referred linear space when possible (e.g. ACEScg, linear Rec.709) for the most accurate color math.
This tool is ideal for building scene-referred film looks and should be used early in your color management pipeline.

Final Thoughts

This 3×3 Matrix Maker workflow is a valuable tool for filmmakers and colorists interested in authentic film emulation, matching digital cameras to analog film stocks, or learning the math behind color matching.

With just a few steps, you can build a mathematically sound color transform and load it directly into Resolve using only Python, EXRs, and the chart images.

3×3 Matrix Match between ARRI Camera and EXR 100T Filmstock

Left with 3×3 Matrix Match and Kodak 2383 LUT / Right Only Kodak 2383 Lut

Gardner, Zeb. “Genetic Color Space Transform Optimization Algorithm.” Zeb Gardner, October 6, 2024. Accessed July 19, 2025. https://www.zebgardner.com/photo-and-video-editing/genetic-color-space-transform-optimization-algorithm.

DeMystify Colorgrading. “Film Profile Journey: 21 – mmColorTarget For Resolve.” DeMystify Colorgrading, n.d. Accessed July 19, 2025. https://www.demystify-color.com/post/film-profile-journey-21-mmcolortarget-for-resolve.