What should be considered about the lighting problem of membrane structure building?
Artificial light at night
When using artificial light source, people feel different about the space covered by film at night. If internal illumination is used, the building will become a striking illuminant in the sky at night. Because of the translucency of the membrane material, it is not as effective to irradiate the inner space by irradiating the membrane surface upward. So artificial light at night should only be used on the surface of the film.
Depending on the type of membrane material used, a lot of light will penetrate from the inside to the outside of the membrane. Therefore, it is necessary to use low light as the main light source to irradiate the lower space. In this light, the shadow is different from that of the day, and the light is not soft. However, in the night, the upward light is very important for the clarity of membrane structure. They must complete the task of indirect light source in the day at night. Therefore, the upward light should also shine on the surface of the film from a shallow angle to emphasize the texture and shape of the film.
Because of the overlap between the film materials, the light transmittance of the welding seam is lower than that of the single-layer film beside the welding seam, so they form a dark strip on the surface of the film. The human eye is very sensitive to contrast. Because of the indirect light source and the stereo effect of the human eye, this kind of weld is very clear, and as a part of the film surface, they enhance the surface effect of the structure along the hyperbolic geometry.
These welds stand out during the day, increasing the clarity of the shape, but are less pronounced at night than during the day. If these welds are required to enhance shape clarity at night, the membrane roof should be illuminated from the outside.
Both sunlight and artificial light have an important influence on the space covered by any film. Due to the special translucency of membrane materials, the use of light plays an increasingly important role in tensile structures. If in the design process, the attention to the characteristics of light is not enough, then the completed building will be very uncomfortable, so even if the membrane surface is bright, its interior is very black or dark, even claustrophobic. However, if a designer knows how to use the special properties of membrane materials to play a better role, the result will be a good illumination of the internal space, forming an almost magical effect.