Gonioreflectometer

A gonioreflectometer is a device for measuring a bidirectional reflectance distribution function (BRDF).

The device consists of a light source illuminating the material to be measured and a sensor that captures light reflected from that material.

The light source should be able to illuminate and the sensor should be able to capture data from a hemisphere around the target.

The 'gonio' part of the word refers to the device's ability to measure at different angles.

Most of these devices use a camera instead of the light intensity-measuring sensor to capture a two-dimensional sample of the target.

Traditional non-image based lab gonioreflectomer with goniometric arms for positioning the light source and detector. Depicts sample and calibration coupon stages on moveable platform.
The University of Virginia spherical gantry, an example of a modern image-based gonioreflectometer