Final answer:
Increasing the thickness of the screen in a film-screen system affects the interference patterns produced. Thin films are more effective in producing destructive interference, reducing the intensity of light over a broader range of incident angles. These thin films are known as non-reflective coatings.
Step-by-step explanation:
Increasing the thickness of the screen in a film-screen system has an effect on the interference patterns produced. As we noted before, interference effects are most prominent when light interacts with something having a size similar to its wavelength. A thin film is one having a thickness t smaller than a few times the wavelength of light. Films are most effective in producing destructive interference when the thinnest layer is used, since light over a broader range of incident angles will be reduced in intensity. These films are called non-reflective coatings, but this is only an approximately correct description, since other wavelengths will only be partially cancelled.