TABLE OF CONTENTS:
The Look: Moving from “Show LUTs” to LMTs
The Camera: Protecting the captured image
The Display: Preserving the look across displays
AMF as the Color Recipe: Putting it all together
INTRODUCTION
Authoring the images of a film or TV show involves two main phases: developing the look and protecting the look throughout every production stage.
At Netflix, we believe this aesthetic look is a fundamental part of our filmmakers’ story, and our goal is to ensure that the creative vision developed on day one is preserved all the way to the member’s screen.
Historically, moving the creative look from the DoP or colorist, to the on-set DIT cart, to the edit suite, into color finishing has been a fragile process. Productions are forced to rely on difficult-to-scale, custom LUT tracking methods, proprietary databases, or endless email chains. Consequently, looks are often baked-in, or completely lost in translation between different phases. Too often, this results in suboptimal images or forces filmmakers to spend valuable time solving technical problems instead of focusing on creative decisions.
“Lost in LUTs”
This article focuses on enabling our productions to develop and protect their look, through the use of open standards like ACES 2 and its color interchange format, AMF (ACES Metadata File), and demystifying these technical concepts to help productions achieve their creative goals.
DEVELOPING THE LOOK
We believe the creative process for developing a look should be unconstrained. The paint brushes, canvas, or box of crayons used is an artistic choice. Whether you use traditional 3D LUTs, a bespoke film emulation algorithm, or advanced color grading tools, the choice is yours.
But however the look is developed, it must be protected across the many phases of production. This is where ACES comes in.
PROTECTING THE LOOK
The ACES framework acts as a protective layer for your creative intent. It is the leading industry standard for color management, and its open-source nature means it is built into all major products used during production.
There is a common misconception that ACES itself has a specific look, that you are forced to use. While it is true that it has a “base look” in its default rendering - as all color management frameworks do - it is designed to accommodate any creative look or LUT. More on this later (see FAQ for more detail).
In short, ACES is a technical standard, not a creative one. It is designed to preserve the highest quality “digital negative” of your images, and allow for the greatest flexibility in creative looks.
INTERCHANGING THE LOOK
Now that we have a look, and a framework for protecting it, how do we actually communicate that look across the various software used in the workflow?
This is where the rubber meets the road with AMF (ACES Metadata File).
AMF acts as the “color recipe” - designed to replace the often ambiguous CDLs and LUTs common in today’s workflow. It is a lightweight XML sidecar file (.amf), which travels with your footage, ensuring that nothing gets lost in translation across the production.
USING AMF
AMFs consist of three main components:
- The Camera
- The Look ← the focus of this article
- The Display
Let’s start with the Look.
THE LOOK: Moving from “Show LUTs” to LMTs
One of the most powerful components of the ACES framework is the LMT (Look Modification Transform). It is the “creative look” in the ACES framework.
Example of a Film Emulation LMT (left)
A common practice today is the development of a “Show LUT” - which is a pre-baked LUT (usually .cube) representing the whole color pipeline, baked into a single 3D LUT.
While this is useful, it is limited in flexibility, and largely a “black box” of color decisions, with no standardized way to track them.
In an ACES pipeline, the look component is called the LMT (Look Modification Transform), which can support any creative look, applied in the ACES color space.
As you can see, represented as an LMT, the look is now a “universal look” - it can be used across any camera or display.
| NOTE: Cameras are mapped into ACES using an Input Transform (IDT), the look is applied, and then mapped to the display using an Output Transform (ODT). More on this in later sections. |
Another difference is that LMTs are stored as .CLF (Common LUT Format) - a modern LUT format providing more precision than traditional 3DLUT formats like .CUBE and others.
And importantly, the look is now trackable via AMF as part of the “color recipe”.
Example AMF recipe with a custom LMT (.clf)
How do I develop my look like this?
There are two main approaches to developing a look as an LMT:
Native Look:
Developing an LMT can be as simple as setting up a color grading project in ACES mode, creating the look, and exporting an AMF. This will export your AMF “color recipe” and any CLFs that are part of the grade.
| NOTE: Any primary CDL corrections will be stored as CDL values inside the AMF, while any secondary or more complex color grading operations will be stored as an LMT (.CLF). Any spatial operations or “power windows” will be ignored, similar to exporting a LUT. |
This is recommended for most productions who are developing a look from scratch, and requires the least expertise and color science knowledge.
Hybrid Look:
An LMT can also be developed to match an existing LUT (such as .CUBE) or even simulate another color management system, but this process requires more expertise. For example, a common approach is to “sandwich” an existing LUT with the Inverse ACES Output Transform, in order to simulate the same visual appearance of a non-ACES LUT in an ACES pipeline.
Example of a LMT “sandwich” of existing LUT
This non-destructive process, particularly with the improvements in ACES 2.0 invertibility, allows any production to achieve any creative look, no matter how it is created, and still gain the benefits of the ACES framework across the workflow.
Example of LMT “sandwich” in DaVinci Resolve to export an LMT
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LMT Maker: To ease the process of creating these Hybrid Look LMTs, Netflix is developing LMT Maker, which is a tool to convert an existing LUT into an ACES LMT. As long as you know the Input and Output Color Spaces of the LUT, this conversion can happen with the click of a button and export a CLF. We expect this to become available to productions later in 2026, but in the meantime, reach out to your Netflix representative if you need assistance. |
THE CAMERA: Protecting the captured image
Now let’s talk about the source or input to an AMF.
On a typical production, there is a primary camera, used for the majority of captured footage, and secondary cameras for various use cases (drones, crash cams, witness footage, etc).
The first step in any color-managed workflow is to unify all cameras into a common working color space. With ACES, this is provided by the IDT (Input Device Transform).
In an AMF, this is tracked either with:
Official IDTs: AMF supports all major digital cameras which have official IDTs (e.g. ARRI, Canon, RED, Sony, etc).
Example of an official IDT stored in the AMF
Custom IDTs: AMF also supports the use of Custom IDTs, for cameras that do not have official IDTs, which are tailor-made for a specific camera. Similar to looks, these are stored as .CLF files and linked within the AMF.
Example of Custom IDT stored as a CLF
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IDT Maker: To ease the process of creating IDTs for secondary cameras, Netflix and the Academy co-developed a tool called IDT Maker, allowing you to shoot a series of exposures of a Macbeth color chart, and export an IDT. It can also be used to generate CLF versions of IDTs for color spaces with published specs. We expect this to become available to productions later in 2026, but in the meantime, reach out to your Netflix representative if you need assistance. |
THE DISPLAY: Preserving the look across displays
Now let’s talk about the last part of the AMF recipe: how was it viewed?
Images are viewed across a variety of displays during a production. In the context of ACES, this is handled by the ODT (Output Device Transform). This is an essential part of the AMF “color recipe” that stores exactly what display it was viewed on.
Additionally, with the improvements in ACES 2, these output transforms offer an improved, color-appearance based rendering, and better perceptual match across any different displays (including HDR and SDR).
An LMT can be viewed in either SDR or HDR
Because the look is independent of the display via the LMT, your look will be preserved no matter how it is viewed. This is especially important these days with a mixture of HDR and SDR displays being used across productions.
AMF AS THE COLOR RECIPE: Putting it all together
Now that we have a color pipeline defined by our look, the camera, and the display, this forms a full, unambiguous record of the “color recipe” for a given shot.
Example of full AMF recipe
AMF is now a lightweight sidecar “color recipe” - containing your exact creative intent - which can travel with your footage, whether it is between departments, vendors, or ingested into Netflix’s Content Hub.
EXAMPLE LIFECYCLE OF AMF
- DP and Colorist develop a look
Ideally during pre-production, a creative look is developed with the DoP and colorist. This can happen in an ACES project and simply export an AMF (aka “Native Look”). If the look is developed outside of ACES, or an existing LUT match is required, it can be converted into a LMT and then exported as AMF (aka “Hybrid Look”).
Both are supported in the latest versions of Davinci Resolve and Baselight.
Think of this like the AMF “template” of the show’s look. This is the crucial step of the workflow when the look is created, exporting AMF so that all downstream recipients have the full “color recipe”.
- DIT imports the look on-set
The DIT sets up their on-set grading system in ACES mode (such as Pomfort Livegrade) and imports the AMF. This automatically sets up their color pipeline with the correct setup.
At wrap, the DIT exports AMFs from their look library which now includes the <clipID> based on the clipname from the camera (if supported over SDI). Alternatively, they may also offload the camera cards themselves and associate AMFs to clips at this stage (such as Pomfort Silverstack) .
- Dailies receives the look
The footage is sent to a Dailies system where the camera rolls are loaded, and, if done correctly, the AMFs can be imported and automatically populate the color for every shot (such as in Colorfront OSD) via the <clipID> inside the AMF.
At this stage, depending on if dailies are applying or adjusting color, they may export new AMFs from the dailies system. In practice, it is best to export per-shot AMFs at this stage regardless of whether the grade has changed to ensure it is a record of the color decisions applied to Dailies.
- Delivery to DI, Netflix’s Content Hub, or others
AMFs are transferred with footage and linked via <clipID> for delivery with Conform and VFX pulls. The AMF color recipe can now travel with footage (OCF or EXR) to any vendor who may receive pulls, and have a full record of the creative intent.
CONCLUSION
The aesthetic look of a film or TV show is a core part of its storytelling, but keeping that look consistent across production has traditionally been fragile and difficult to manage.
ACES and AMF work together to solve this challenge. ACES provides a stable foundation for protecting the look, while AMF ensures the creative decisions that shape the image can be interchanged seamlessly across the many phases of production. Together, they replace guesswork and manual reconstruction with a clear, reliable color workflow.
FAQ
See FAQ: Utilizing AMF in an ACES Workflow.