A method for producing an image sensor comprises: depositing a first back-end-of-line, BEOL, layer above a substrate comprising an array of light-detecting elements, said BEOL layer comprising metal wirings being arranged to form connections to components on the substrate and together with depositing the first BEOL layer, improving planarization of the first BEOL layer by depositing a planarizing metal dummy pattern in the first BEOL layer, wherein a part of the planarizing metal dummy pattern is arranged above a light-detecting element, wherein the planarizing metal dummy patterns is formed from the same material as the metal wirings and is deposited to planarize density of the metal deposited in the first BEOL layer across a surface of the layer and wherein a shape and/or position of the metal dummy pattern above the array of light-detecting elements is designed to provide a desired effect on incident light.