The light transmission of architectural fiber membranes is often considered to be the most valuable feature of tensile membrane structures. During most of the daytime, the spectral transmittance of the film (typically 10% to 15%) provides the possibility of not using artificial lighting, thus saving a lot of energy to compensate for higher heating energy consumption.

      Although the indoor illumination is high, the illumination is only one of many factors that form the indoor visual environment. The selection of membrane materials, structural topography and detailed structures all have important effects on the visual environment. Therefore, the visual environment of the building should be taken into account in the preliminary design stage. In addition to meeting the illuminance requirements for indoor activities, the users' perceptions and other subjective needs should also be met. Light characteristics.

1. High lighting factor
      The sunlight that hits the roof is transmitted into the room in the form of diffuse light. From the inside, the roof becomes a continuous bright surface, and its strength changes due to the relative position of the roof and the sun.
The daylighting coefficient of the indoor space of the tension membrane structure (ie, the ratio of the natural light level of the indoor and outdoor surfaces) can generally be as high as 10%; while in traditional buildings, the light can only enter the room from a limited light window, and its lighting factor is less than 3 %. Even on cloudy days, the light level in the membrane structure can meet the basic requirements of most activities.

2. No glare
      Since the transmitted light and the reflected light entering the film structure room are diffuse light, glare is less likely to occur, but the arrangement of the glass lighting area and the shade should be taken into consideration to avoid glare caused by the direct light thereof.

3. The color feels good
      People in the room will have a good color perception of white or beige materials, because these two colors exhibit a characteristic of linear spectral transmission of visible light. The degree of transmission increases with the wavelength of the transmitted light, which makes the transmitted light slightly warmer than the emitted light. The transmission spectrum is related to the fiber and its properties, the thickness of the coating, and the additional surface layer, and the manufacturer should give more detailed information. Relative to coated PVC. The transmission spectrum of the polyester fiber membrane and the PTFE-coated glass fiber membrane is more uniform.