By replacing the front flange of the sensor with a fiber optic adapter, the integrating sphere is easily used be measure fibers. These fiber optic adapters are available for all models of Ophir spheres. Because the typical output from an optical fiber is slowly diverging, the first reflection spot at the opposite side of the source is not highly concentrated. Therefore, often either collimated beam configuration or the divergent configuration is fine. However, in case of lensed fiber, the divergent beam configuration is recommended due to the increased NA of the fiber. In case of using a fiber collimator, the collimated beam configuration is recommended.