ILM open-sourced OpenEXR and it became the VFX industry's image standard

Working on Star Wars: Episode I in the late 1990s, ILM found its 8-bit image format could not hold both the darkest shadows and brightest highlights of real scenes, crushing one end or the other.

Florian Kainz and Rod Bogart created a 16-bit floating-point format — OpenEXR — with over 30 f-stops of range, and defined it through an API rather than a bit-layout description, borrowing OpenGL's principle that you shouldn't have to know about features you don't use.

After battle-testing it on Harry Potter and the Sorcerer's Stone and other films, ILM released OpenEXR as open source in January 2003. The industry adopted it quickly; Apple built support into macOS, and it fed the Academy's ACES color project.

Ship the format as working code, not paper

A working library, not a paper spec, made adoption cheap.

Half-float doubled dynamic range without doubling memory.

Open source made third-party tools add support voluntarily.

ILM's prestige gave the format credibility.

To make a proprietary format the industry standard, give it away as clean, working code: an API people can link beats a paper spec people must reimplement, and Lucas's blessing made it safe to adopt.

OpenEXR is now an Academy Software Foundation project and the standard HDR interchange format across VFX and animation, used wherever images are made to make more images.