Darkfield Illumination is a transmitted light technique that uses oblique light to illuminate the sample. Background light (non-sample light) is not collected by the objective, which results in a dark background. Light that interacts with the sample (sample light) is scattered (refracted, reflected, and/or diffracted). Some of this scattered light is collected by the objective and is seen as light spots or areas on a dark background. Contrast is therefore generated, and the sample visualized.