1. The problem statement, all variables and given/known data A lens (##\mu##=1.5) is coated with a thin film of refractive index 1.2 in order to reduce the reflection from the surface at ##\lambda=480 nm##. Find the minimum thickness of the film which will minimize the intensity of reflected. [Assume near normal incidence] 2. Relevant equations 3. The attempt at a solution I don't really know how to begin with this. It looks to me that this is related to thin film interference but I have never dealt with three different mediums while solving problems related to this.