Methods for producing phosphor based light sources are disclosed. One method includes measuring an excitation light output of an LED, forming a plurality of phosphor film articles, measuring an optical characteristic of each of the plurality of phosphor film articles, selecting one of the plurality of phosphor film articles based on the LED excitation light output and measured optical characteristic of the one of the plurality of phosphor film articles to obtain a desired emission light output from the phosphor film article when the phosphor film article is positioned to receive the excitation light, and positioning the phosphor film article to receive the excitation light.