EULUMDATLDT

EULUMDATLDT is a term found in some lighting design workflows to denote a data package that combines EULUMDAT photometric data with an LDT component. There is no widely adopted standard by that exact name in major photometric references, and the term often appears in vendor-specific documentation or as a shorthand for a project file that pairs EULUMDAT photometry with supplementary LDT metadata.

EULUMDAT is a European standard format for photometric data that describes the luminous intensity distribution of a luminaire as a function of angles. It is a plain-text format used to convey how light is emitted in different directions, enabling accurate modeling of a fixture’s performance in lighting software. EULUMDAT data typically includes information about the luminaire geometry, scale, and angular distribution, and is widely supported by many design and analysis tools.

LDT, in this context, refers to a text-based component used by some tools to describe additional luminaire metadata, mounting recommendations, or references to photometric data files. The LDT portion can contain descriptive fields such as manufacturer, model, and file references, providing context that complements the photometric data.

In practice, EULUMDATLDT may appear as a bundled or linked dataset where an EULUMDAT file and an LDT file are used together to streamline imports in certain software environments. Interoperability depends on software support; some tools can import EULUMDAT and read accompanying LDT metadata, while others require format conversion or separate file handling. Users should consult their software’s documentation to determine compatibility and best practices for combining these data components. See also EULUMDAT, LDT, and photometric data formats such as IES.