A LEN file is an effects file used by ERDAS IMAGINE, a geospatial data authoring application widely used by archaeologists, engineers, biologists, geologists, inspectors, and soil scientists. It contains lens flare effects that can be added to a 2D or 3D scene in IMAGINE when imported.

IMAGINE comes with various tools for spatial modeling, map production, mosaicking, parallel batch processing, and change detection. However, it is mainly used to create 2D and 3D images, 3D movies, and cartographic-quality map compositions from geospatial data. LEN files are used to add realistic light effects to a 2D or 3D image created in IMAGINE. The lighting effects simulate the effects created when a camera lens is viewing a light source, such as the sun or a fire. You can add a lens flare to your scene by selecting File → Lens Flare Layer... and navigating to the LEN file.