This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
Specularityphongshowcase. en Array of images of sphere showing the effect of Specularity on rendered image using the phong model Hardness increases from top to bottom The amount of Specularity increases from left to right de Renderings einer Kugel mit verschiedenen Einstellungen der Spekularitt in einem PhongBeleuchtungsModell