One LUT file extension covers two documented histories

The image

The reference object is a two-page specification document, the Cube LUT Specification Version 1.0, published by Adobe Systems in September 2013 and preserved via the Wayback Machine after its original hosting page went offline. It sets out a plain-text file format for storing a look-up table used to convert one set of color values into another. Blackmagic Design's current DaVinci Resolve reference manual describes a second, independently documented .cube implementation.

What the documents show

Adobe's specification states that the Cube format was originally developed by IRIDAS in 2003, and that the 2013 document was written to capture previously undocumented details evident only in IRIDAS and Adobe implementations, in order to secure broad interoperability. It defines required keywords, TITLE, DOMAIN_MIN, DOMAIN_MAX, LUT_1D_SIZE, LUT_3D_SIZE, a mandatory .cube file extension, and a table size limited to between 2 and 65,536 sample points per dimension. The DaVinci Resolve manual, describing a different lineage of the same file extension, states in a note that Resolve exports LUTs in a .cube format that is, in the manual's own words, a DaVinci-developed LUT format with no relation to the Adobe SpeedGrade .cube format, while also documenting that Resolve reads and exports 1D and 3D .cube tables at 17, 33 or 65 points per axis. The two documents therefore describe the same three-letter extension serving two documented, and according to Blackmagic's own manual, unrelated technical histories.

Production context

This is an editorial synthesis of what both documents state. For a pipeline moving a look between a grading system and a rendering or preview tool, the practical consequence is that a .cube file's compatibility cannot be assumed from its extension alone; the manual's own note exists precisely because two applications built on this extension without one shared governing body maintaining it.

Reference versus imitation

Citing the .cube specification as though a single authority defines the format for every tool overstates what these documents establish. Adobe's document is a published specification carrying its own file extension requirement and sample keywords; DaVinci Resolve's is one vendor's implementation notes describing a separate origin. Crediting a LUT format correctly means naming which document and which vendor's implementation is being described, not treating .cube as one settled standard.

• Does a cited LUT reference name the specific format document, or only the shared file extension?
• Is the DaVinci-developed .cube variant being distinguished from the Adobe-published Cube LUT Specification?
• Was the specification retrieved from a live page or an archived copy, and is that distinction noted?

Both documents are narrow and technical: one specifies a text file format, the other documents how one application implements a similarly named but separately developed format. Neither supports treating .cube as a single governed standard shared identically across every tool that reads it.