The lens hood can prevent the entry of non-imaging light and avoid haze during backlight, side light, flash or night photography. During front light and side light photography, it can avoid surrounding scattered light entering the lens. During light photography or night photography, it can avoid ambient interference light entering the lens. It can also protect the lens from scratches, fingerprint, and prevents from wind, sand, rain and snow to some extent.Compatible for EF 24-70mm f/4l L IS USM lens. Lens hood are widely used in backlight photography and are generally used to avoid glare. However, glare may occur if the light source is in close proximity. At this point, you can use your hand on the side of the light source to block the hood. Whether glare is eliminated or not, it can be observed clearly from the viewfinder.