Excerpt: Although I was on the cuff about purchasing Canon's lens hood versus a third party hood, in the end I am happy that I did. No worrying about whether the hood would fit correctly or whether a lack of felt interior would generate flare (a potential problem on third party hoods).
Pros: Consistent Output, Durable, Rugged, Strong Construction
Excerpt: Fits well and does what its supposed to do. The only problem I have with it is that the lens now takes up extra room in my camera bag even when reverse fitted. Which means I have to leave something else at home now or get a bigger bag.
Excerpt: I bought this for a EF17-40 lens used on a crop body and it works great. Also have a ET-83II that came with my EF70-200 F2.8 and it still fits like new, so I wouldn't think of buying a non-Canon hood. A little pricey for what it is, but no regrets.