Brightfield Illumination Eye Eye Ocular lens 。Dark objects are Objective lens Only light reflected by the specimen is visible against a captured by the Specimen objective lens bright background. Unreflected light Condenser lens Light reflected off the Opaque disc specimen does not Light Light enter the objective lens. (a)Brightfield (b)Darkfield Figure 3.4a,b • Dark objects are visible against a bright background. • Light reflected off the specimen does not enter the objective lens. Brightfield Illumination Figure 3.4a, b