A specular variable angle absolute reflectometer includes a light source and a mirror system in a light path of the light source. The mirror system is configured to reflect a light beam from the light source towards a sample that is optically reflective. The device also includes an elliptical roof mirror disposed in the light path after the sample having an ellipsoidal reflector surface configured to reflect the light beam back towards the sample. The device also includes a mechanism connected to the elliptical roof mirror. The mechanism is configured to rotate the elliptical roof mirror about an axis of the sample. The device also includes a detector in the light path after the elliptical roof mirror such that the detector receives light that has been reflected from the elliptical roof mirror, thence back to the sample, thence back to the mirror system, and thence to the detector.