Canon 100-400L - manual focus ring jammed

Has anyone ever seen this before? I have a 100-400L which has a totally jammed manual focus ring. The zoom (which is the same ring of course) works fine, and the autofocus works fine , but the manual focus just doesn't budge at all.

Any ideas how this could have happened? Any alternatives to a quick trip to Canon at Elstree? Do you think the warranty is likely to cover it?

Are you sure it's the focus ring and not the zoom lock ring? The zoom is push/pull so there is no ring for zooming. THe focus ring and barrel lock are right next to one another.

gjl711 wrote in post #7015411
Are you sure it's the focus ring and not the zoom lock ring? The zoom is push/pull so there is no ring for zooming. THe focus ring and barrel lock are right next to one another.

Yes I'm quite sure. I have 15 of these lenses.

Try loosening your tripod collar - overtightening that can restrict the movement of focusing gears on some lenses.

StewartR wrote in post #7015530
Yes I'm quite sure. I have 15 of these lenses.

Ok, I had to ask.

StewartR wrote in post #7015530
Yes I'm quite sure. I have 15 of these lenses.

Did you get a discount

perryge wrote in post #7015544
Try loosening your tripod collar - overtightening that can restrict the movement of focusing gears on some lenses.

You're kidding, right? This is the 100-400L we're talking about. The tripod collar and focussing ring are in completely different places.

StewartR wrote in post #7015673
You're kidding, right? This is the 100-400L we're talking about. The tripod collar and focussing ring are in completely different places.

I know that. But the tripod collar can apply pressure to the internal gears if tightened too much - it's happened to me before on my 200L, and when I loosened the collar the MF ring became unstuck and started working again. I'm not saying this is the solution but is it not even worth a try?

So no, I was most definitely not kidding - no need to be rude. If it doesn't work, just send it in because then I have no other suggestions, but if it does, I saved you a trip to Canon. Owning a lens rental business doesn't give you the automatic authority to poo-poo the advice of others who are genuinely trying to help.

perryge wrote in post #7015686
So no, I was most definitely not kidding - no need to be rude. If it doesn't work, just send it in because then I have no other suggestions, but if it does, I saved you a trip to Canon. Owning a lens rental business doesn't give you the automatic authority to poo-poo the advice of others who are genuinely trying to help.

I wasn't intending to be rude, Perry, and I'm sorry if it came over that way. I appreciate that you're trying to help and I'm grateful.

Your experience of the 200L is interesting, and surprising. But unfortunately it doesn't translate over to the 100-400L. The focus ring and the focussing unit in the 100-400L are way down the front of the lens, and the tripod collar doesn't affect that part at all.

(Plus, I just tried it anyway. )

^ Ah ok, then I'm out of ideas, you've probably gotta send it in.