Lightroom - How To Add Film Grain

Film Grain is often referred to as granularity and dates back to photographic film processing. Historically it was due to the presence of small particles of metallic silver developed from silver halide during the processing procedure. In digital photography, the effect of Film Grain is sometimes added for aesthetic effect, as digital photos are often perceived to be too clean and/or sterile. It is an effect that is particularly powerful in Black & White photography.

Adding grain works particularly well if you are processing Black & White images. If you want that retro look to your own photographs, just open the Effects panel, and adjust the Amount slider to get the level of granularity you desire. You can also adjust the Size and Roughness of the effect using the respective sliders.