Canon EW-83E lens hood is primarily developed to avoid unwanted stray light from passing through the lens by lengthening and shading the end of the lens. In addition, since the end of the lens is lengthened, you also get the added advantage of some additional safety from unintentional impact. The "petal" shape of Canon EW-83E maximizes the amount of hood coverage for the minimum amount of weight and hood area. The Canon EW-83E hood is developed to match the specific focal length of the lens it was designed for. Canon EW-83E lens hood is the most important accessory for each lens you possess. The Canon EW-83E gives various functions: it shades the lens from stray light, enhancing your contrast and image quality; in inclement weather, it can help in keeping moisture or wind-blown debris off the lens. The Canon EW-83E hood can also guard the front barrel from the inevitable impacts against walls, door frames, and other real-life obstacles.