Lens hood offers several benefits to the photographer. Primarily the hood shades the lens from stray light that may result in an unwanted discoloration or hazing of the image, or the appearance of lens flare; shading your lens helps improve contrast and image quality. Also, it offers limited protection from keeping moisture and wind blown debris off the from lens element and adds extra protection from accidental impact. For Tamron 70–180mm f/2.8 Di III VC VXD G2 lens Designed to prevent unwanted stray light from entering the lens Ensures no problems with vignetting or motor functions Added benefit of extra protection from accidental impact
