So they put a veiling cloth over the field of stars. When the cloth is lit by exterior light, only the veiling cloth is seen. But in the shadow of the exterior light, the stars can be seen through the veiling cloth by being back-lit. Would this be the trick?
So they put a veiling cloth over the field of stars. When the cloth is lit by exterior light, only the veiling cloth is seen. But in the shadow of the exterior light, the stars can be seen through the veiling cloth by being back-lit. Would this be the trick?