The ES-71II Lens Hood for Canon 60D T3i T2i T1i T3 XTi XT XSi with EF 50mm f1.4 USM is to prevent light from hitting the front lens element from the sides.So the ES-71II could reduce contrast and creating flare. Pictures taken with this lens hood installed can have richer colors, deeper saturation.
A secondary use for ES-71II Lens Hood for Canon 60D T3i T2i T1i T3 XTi XT XSi with EF 50mm f1.4 USM is to protect the lens. The damage prevented can range from a finger-printed front element to a broken front element.The Lens hoods are generally strong and stick out from the lens some distance. Accidental touches and scratches to the front element are reduced simply because the glass is difficult to reach. Some impact protection is gained from having a sacrificial part taking the blow. Of course, ultra wide angle lenses have very short hoods that offer very little protection.
The ES-71II Lens Hood for Canon 60D T3i T2i T1i T3 XTi XT XSi with EF 50mm f1.4 USM provide more front lens element protection from rain and dust. Of course, if your lens is not weather sealed, you should not let it get wet in the first place. A clean and dry front element will allow the camera to shoot the better image quality you expect.
The ES-71II Lens Hood is High quality lens hood and for Canon lens
EF 50mm f/1.4 USM