“Corrosion” performance of an optical filter is enhanced when a relatively thick zinc-based film functions as a seed layer for a subsequently formed silver-based film. At least two pairs of dielectric and metallic layers are included within the optical filter, where the zinc-based film is a second film of the dielectric layer and where the silver-based film is the metallic layer. The zinc-based film has a zinc content of at least 80 percent and has a thickness of at least 15 nm. In order to further improve the corrosion performance, gold may be incorporated into the silver-based film.