A system is configured to perform metrology on a front surface, a back surface opposite the front surface, and/or an edge between the front surface and the back surface of a wafer. This can provide all wafer metrology and/or metrology of thin films on the back surface of the wafer. In an example, the thickness and/or optical properties of a thin film on a back surface of a wafer can be determined using a ratio of a greyscale image of a bright field light emerging from the back surface of the wafer under test to that of a reference wafer.