Durchschein

Durchschein is a German term describing the optical property of a material to allow light to pass through to varying degrees. The word combines durch (through) and scheinen (to shine) and is used in both everyday speech and technical contexts to describe how clearly or obscurely objects on the opposite side can be perceived. In technical literature the concept is related to transparency, translucence, and opacity, with Durchschein often serving as a general reference to light transmission.

In scientific terms the relevant quantity is transmittance or Durchlässigkeit: the fraction of incident light that emerges on the far side of a material. Transmittance depends on material thickness, composition, and the wavelength of light; it is reduced by absorption and scattering within the material. Measurements are typically carried out with spectrophotometers that report transmittance as a percentage across wavelengths, yielding a spectral profile of the Durchschein.

Materials can exhibit a range of Durchschein. Transparent materials transmit light with little scattering, allowing clear image reproduction. Translucent materials transmit light but scatter it, producing a diffused silhouette. Opaque materials block most light. Practical examples include clear glass or acrylic (high Durchschein), frosted glass or tracing paper (moderate Durchschein), and certain textiles or opaque plastics (low Durchschein).

Applications of the concept span design, architecture, and materials science. Designers use varying Durchschein to control privacy, lighting quality, and visual weight; in engineering, material choice hinges on desired transmittance under given thickness and wavelength conditions. See also transparency, translucency, and opacity.