Transmitted Light Differential Interference Contrast (DIC) is an illumination technique which, like Phase Contrast, enables specimens that have a refractive index similar to their surroundings to be visually differentiated. This is an interference technique which relies on Polarized illumination. Wollaston prisms placed in the condenser and in the back focal plane of the objective modify the normal extinction resulting from the crossed polarizers to create a 3D effect of the specimen’s surface. A DIC Turret condenser will usually have a Brightfield position as well as DIC positions to match each objective.