A four-number grade format outlived the tools that wrote it

The image

The record is not a still but a small piece of XML: a DaVinci Resolve 21 Reference Manual example of a Color Decision List file, carrying the namespace urn:ASC:CDL:v0.5 and a single ColorCorrection block with Slope, Offset and Power values. The manual, retrieved on 16 September 2026, documents how Resolve reads and writes files in this format; a separate ACEScentral knowledge-base article on the Common LUT Format lists the ASC CDL as one of several operator types a CLF file can encapsulate.

What the documents show

The manual states that a CDL exchanges basic primary color information from one application to another, and documents exactly four parameters, described as how the American Society of Cinematographers encode color information: Slope, Offset, Power and Saturation. It gives the underlying math directly, output equals input multiplied by Slope, plus Offset, raised to the power of Power, and documents three related file extensions, .cc for a single correction, .ccc for a collection, and .cdl for a decision list tied to specific shots. The ACEScentral article, describing the Common LUT Format, corroborates that ASC CDL is a recognized, distinct operator type alongside matrices and 1D or 3D look-up tables in current color-pipeline documentation, rather than a superseded or one-vendor scheme. Neither document describes the CDL as capturing secondary corrections, power windows, curves or any spatially selective adjustment.

Production context

This is an editorial reading of the documented parameters. A four-number, plain-text correction that any application can read is well suited to one specific job the manual implies throughout its ColorTrace chapter: carrying an on-set look approximation from a data-management cart into dailies, editorial and visual-effects review, where every recipient needs the same starting reference rather than an identical final grade.

Reference versus imitation

Because the documented format is limited to four global parameters, describing a CDL as preserving the grade from set to finishing overstates what the standard carries; the manual's own math shows a single global operation applied uniformly across an image, with no provision for the windows, secondaries or tracked adjustments a finishing colorist typically adds. Citing a CDL correctly means citing a primary color starting point, not a finished look.

• Is a CDL being cited as a starting reference, or mistaken for a complete creative grade?
• Does the citation name which of the three file types, .cc, .ccc or .cdl, is meant?
• Is the CDL's four-parameter scope being distinguished from the broader Common LUT Format that can also carry it?

The documented record is narrow and mathematical: four parameters, one formula, three file extensions. It supports describing a CDL as an interchange format for a primary color starting point, not as evidence of a finished, credited creative grade.