Nx 3-Strip (Technicolor Process 4) for DaVinci Resolve

[Moderator Note: Please keep comments on this thread related to the Nx 3-Strip tool. General Technicolor process discussion is available here and here.]

Hello Everyone,

I wanted to share a tool I’ve been developing called Nx 3-Strip. It’s a DCTL specifically engineered to reconstruct the authentic physics of the Technicolor 3-Strip (Process IV) pipeline natively inside Resolve.



Please checkout https://nxcolor.com/3-strip for more information! [link corrected]

Built from the physics of the three-strip dye-transfer process.

DCTL that reconstructs the iconic three-strip photochemical process from the ground up. Instead of applying a static color transform, Nx 3-Strip uses physics-based modeling to simulate subtractive dye behavior, spectral separation, and the optical characteristics of historical film printing. By recreating the entire analog pipeline—from light separation to dye interaction and optical diffusion—it produces the dense reds, luminous highlights, and organic imperfections that defined classic cinema. From subtle dye glow to mechanical registration jitter, Nx 3-Strip transforms sterile digital footage into a living, breathing photochemical image.

A Demo of the full featured tool is available for download. Also included a detailed manual on the physics of Technicolor Process IV.
I’d love to hear your thoughts, feedback, or answer any technical questions you have about the implementation!

Thanks,
Naveen
 
Hi Naveen,
I downloaded the demo and I my first impression is positive. Renders colors beautifully. I'll get back later with feedback, but out of the box the plugin seems to be very nice. Not sure about the price in a very competitive field though. Best!
 
I tried this on a M2 mac and it worked. Liked the results so I bought it. Now on my own Intel mac the DCTL crashes my whole Davinci. What's wrong?
 
@Ryan McNeal Sorry about that.. I am unable to edit the post.. I've requested mods to change it..

@Thomas Vroege Thanks for the feedback.. Please checkout the updated version (v1.1) which has tonemapping fixes and ACEScct support added.
Hey @Naveen Chandran I am interested in this plugin but it seems like your ACES and DWG tonemapping are not working properly. I am able to get images that look correct when using a Rec709 G2.4 CST directly before the 3-Strip emulation but if I send ACES or DWG into the plugin it clips the highs and does not look correct at all. What is your intended workflow with this plugin? Being limited to R709 only seems like a major issue and likely will not allow your halation and other spatial effects to work properly.
 
Hello all,

Please checkout the new update Nx 3-Strip V2
v2.0 — Major update.

What’s New

Expanded Input Format
— Replaces Input Encoding with a new Input Format selector covering 15 camera color spaces including ARRI LogC3/LogC4, Sony S-Log3, Canon C-Log 2, RED Log3G10, Panasonic V-Log, and more. Gamut conversion is handled automatically.

Wide-Gamut Rendering Fix — Spatial effects now process in the correct domain for scene-referred footage.

IB Print Acutance — New pre-dye sharpening stage that recreates the three-dimensional pop characteristic of original imbibition prints. Adds edge snap and midtone depth before dye processing.

Gelatin Softness — Simulates the resolution limit of the physical gelatin matrix — softening fine surface texture like skin and fabric while leaving edges intact. The diffuse quality unique to real IB prints.

New Dye Physics — Adds Density Coupling and Midtone Dye Boost. Together these model how real dye-transfer color behaves: saturation darkens rather than blooms, midtones carry the richest dye, and highlights desaturate gracefully.

Refined Grain Engine — Improved IB dye grain with smoother large-scale modulation, a new long-range density variation layer, corrected dye-pool skew, and softer reticulation. Re-tuned defaults better reflect the coarser, organic texture of real IB prints.

Major Performance Upgrade — All convolution cores rewritten for significantly faster processing. Approximately 5× faster at 4K on wide-gamut inputs. Halation and bloom now scale correctly to full slider range at any resolution.

Cleaner UI — Redundant enable/disable toggles removed throughout. Several controls consolidated into the new dye physics system.

Technicolor-Nx-3-Strip 1.jpg

Technicolor-Nx-3-Strip 2.jpg
 
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@Roman Strijbos @Thomas Vroege -- The v2 has been updated to disable all the spatial operations by default. This version has been tested on Apple Silicon / Windows (CUDA and OpenCL)
I do not have a Intel Mac to test, but I guess with the spatial operations disabled, this version (v2) should work.

@Ben Cowan The spatial effects and halation has been fixed in this new version and works correctly in scene referred spaces as well.
 
Nx 3-Strip v2.1 is now available.

v2.1 — May 2, 2026 Update.
Scene-Referred Workflow – Fixed highlight clipping when using scene-referred inputs (EXR, LogC, S-Log3, etc.). Fire, specular highlights, and bright light sources now roll off smoothly instead of clipping to white. Highlights retain their natural color — warm tones stay warm, they don’t bleach out.
Tone Curve – Fixed a brightness dip in the tone curve that could cause highlights to briefly get darker before getting brighter.
Gelatin & Dye Diffusion – Each dye layer now has its own diffusion radius, matching the molecular weight of the real Technicolor dyes. Cyan dye spreads furthest, yellow spreads least — creates more authentic color bleed at edges. Blur profile changed to match real imbibition prints.
Film Grain – Shadow grain is now coarser and clumpier than highlight grain, matching real dye transfer prints.
Shadow Desaturation – When enabled, shadows now desaturate toward warm amber instead of cold gray. Matches the warm shadow character of real Technicolor prints caused by film base tint and residual dye staining.
 
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