Soap film pattern- Sodium light-Formation of perforations

The pattern of the soap film are attributed to the Interference of light waves coming from the upper surface and the lower surface of the film as per wave theory of light however investigations have revealed that the patterns of soap film are due to the surface pattern of the fluid layer present on the soap film. A soap film is found to be a composite soap film comprising of two oil layers sandwiching a water layer. As water evaporates the vapour comes out making perforations in the both the oil layers. At the same time the surface pattern on the soap film also keeps changing. As perforations spread at one stage the oil films also collapse.