The ES-2 is a movie digitizing adapter that allows you to easily convert your movie images to digital. With the high pixel count of the 45.7MP D850, the film digitizing adapter allows you to convert both 35mm slides and negatives into digital files. With a lens such as the AF-S Micro NIKKOR 60mm f/2.8G ED attached to the D850, the camera automatically changes colors and saves them as JPEG images. This once time-consuming process with a film scanner can be done much faster. For negative strips use the FH-4 strip film holder with the ES-2 and for slides use the FH-5 slide mount holder with the ES-2.