Stuck Hood on Canon 400mm 5.6L

Has anyon had this problem. The attached hood on my Canon EF 400mm 5.6L USM
lens will not "release" when twisted and is extremely difficult to move. Any
suggestions. One thought I had was to put it in the freezer to see if the
temperature would allow it to release. I'll probably just do the boring
thing and send it to Canon and let some "qualified" person fix it, but am
willing to try any suggestion that doesn't appear too risky.

I used to think the attached hood was a good thing, now I'm wishing it had a
detachable hood like the 70-200 f4 has.

Eric Miller

 

I've had similar problems with mine. And lately it's even developed a
problem with the manual focusing ring. I can turn and turn and it will
barely focus. Something is obviously loose inside. This doesn't
happen when I use auto focus but with the 1.4x attached it's a real
pain.

Having said all that, it's a wonder the lens works at all since I beat
hell out of it.

 

Those lenses have a friction drive on the focus ring to prevent the USM
drive from damage when you rotate the focus ring in opporsition to the
motor. Maybe $80 to repair.

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