A glass lens is coated on one side with a thin film to reduce reflection from the Len's surface. The index of refraction of the thin film is 1.75; that of the glass is 1.50. What is the least coating thickness that eliminates (via interference) the reflections at the middle of the visible spectrum (λ = 550 nm)? Assume that the light is approximately perpendicular to the lens surface. Air n1 = 1.00 MgF2 Class