A substantially isotropic illumination source utilizes a generally spherical, translucent diffuser. The spherical diffuser has an inner wall and a diffusive outer wall. Light is communicated inwardly to the sphere along a first hemisphere. Light is diffused and homogenized by internal reflection within the sphere and communicated outwardly through a complimentary hemisphere. This light, upon being diffused by the external or outer wall is substantially isotropic. The isotropic light so generated is utilized for video inspection of translucent specimens with improved contrast to facilitate detection of flaws therein. Another aspect utilizes a specimen itself as the isotropic diffuser.