Re: canon 24-70 f2.8l usm
Does the 24-70 extend the front element at the wide end? It's been a whilse since I used one but IIRC it's a rather effective hood for a standard zoom due to the way the front element goes backwards as you zoom in. Normally the hood on a standard zoom is setup not to vignette at the wide end so the hood ends up pretty useless at the long end.
Andrew
A designer knows he has achieved perfection not when there is nothing left to add, but when there is nothing left to take away. - Antoine de Saint-Exupéry