The HD-49 Lens Hood from 7artisans Photoelectric increases contrast and clarity by blocking stray light from entering the lens, preventing flare and ghosting. The hood is specifically designed to not cause vignetting in the corners of the image on the 7artisans Photoelectric 55mm f/1.4 lens. With its 49mm threads, it screws into the front of the lens and has the added benefit of protecting the front element from impacts.