Rubber Lens Hood The Professional Rubber Lens Hood is designed to prevent unwanted light from entering the shot by extending and shading the end of the lens. The addition of a lens hood can help prevent flares–those circles of light that can accompany images where a strong light source is just outside the frame. •Extend to full length for use with a telephoto lens. •Collapse midway for wide angle shots. •Collapse completely for macro photography or easy and compact storage.