Texture - A Key Design Element
A key design element, particularly in black and white photography, texture describes the relative roughness or smoothness of a surface. While a rough surface has a more highly textured appearance than a smooth one, it is the correct application of light that enables the viewer to perceive surface details.
Maximum texture can be achieved with a relatively hard light, skimming over the subject from a 90° angle. This technique will enhance texture by increasing local contrast between the lit and shadow side of details on the subject's surface.
Conversely a diffuse or soft light source will reduce texture visibility. The smaller the light source the more specular the light emitted, creating darker shadows and more intense specular reflections.