This camera lens hood is primarily designed to prevent unwanted stray Light from entering the lens by extending and shading the end of the lens. In addition, sine the end of the lens is extended, you also get the added benefit of some extra protection from accidental impact.
Other Thoughts:Not sure if I like the screw thread design, but it works as its supposed to. Construction is solid, and the lens cap still fits on (not as it was intended, but there is a lip in the hood that holds it in place).
Other Thoughts:This works as well as any manufacturer's original lens hood I have ever had. I bought it for my Canon ET-83II EF 70-200mm f/2.8L USM because Canon's own lens hood requires a separate screw-in retainer ring between their hood and the lens' filter threads. This hood fits directly onto the front of the lens without any retainer ring. It looks great and performs perfectly.
Other Thoughts:Not much to say about this little hood.It fits perfectly,and it does what its suppose to do,which is to keep the extra light out, its well made and I'm very happy with it, This little hood works.