Canon 600 F4 repair question.

I was wondering if anyone has had a similar bent lip like this and if so did they have it fixed? Even if it doesn't affect image quality I'd like to know how expensive it would be to repair this. I thought maybe it was something that could be bought from Canon and just unscrew the bent one and reinstall a new one as I'm not sure if this is the ring that actually holds in the front lens element. If it does hold in the front element then obviously Canon would have to do the work.
Any help or opinions would be appreciated.

IMAGE LINK: http://s260.photobucke​t.com …/Canon600bentli​p.jpg.html

Don't laugh, I've had that one before..

I simply bent it back with some pliers (very gently with duct tape on the jaws to protect the rubber)... No problem....

Canon.. Plan on at least $200 shipping and $150 or more to work on it...

Mark H

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Great tip, Mark!
I cannot imagine paying a lot of money just to have something straight instead of crooked. Plus, we all use these lenses with the hood on 100% of the time, so it will never even be seen. And I don't think the little bent part would have any affect on resale value whatsoever . . . so what's to gain by paying Canon to do it?

Those parts are often aluminum (though this lens uses some magnesium, too). Before using pliers, try making a plastic "stake" from an old toothbrush or similar. Use that to push out the bend a little at a time, starting at the center. I've used this method often to straighten lens filter rings.... sometimes simply by gently pushing things back into shape. Other times it required using an "anvil" (piece of wood cut to fit the outer curve of the lens, covered with plastic or rubber to protect the lens finish), and a bit of careful, light tapping on the "stake" with a plastic hammer. I try to avoid that, though, for obvious reasons.

I may want to have the lens checked anyway, since it's obviously gotten a hard knock on the front barrel. That can effect many things... At a minumum watch for any image problems that might be caused by a decentered element or something else bumped out of adjustment.

Good idea AMFOTO1......

amfoto1 wrote in post #16362932
Those parts are often aluminum (though this lens uses some magnesium, too). Before using pliers, try making a plastic "stake" from an old toothbrush or similar. Use that to push out the bend a little at a time, starting at the center. I've used this method often to straighten lens filter rings.... sometimes simply by gently pushing things back into shape. Other times it required using an "anvil" (piece of wood cut to fit the outer curve of the lens, covered with plastic or rubber to protect the lens finish), and a bit of careful, light tapping on the "stake" with a plastic hammer. I try to avoid that, though, for obvious reasons.

I may want to have the lens checked anyway, since it's obviously gotten a hard knock on the front barrel. That can effect many things... At a minumum watch for any image problems that might be caused by a decentered element or something else bumped out of adjustment.

That's what I was thinking of trying. Cutting out a wood frame that matches the outer curve and then gently trying to form it back into shape.
This is actually a lens I just purchased and haven't even received yet. Seller claims no problems and hopefully that's the case. Like a kid on Christmas eve waiting for this. Hopefully I end up loving this lens as much as I anticipate.

I had an old 400 F2.8 with a 2 1/2 inch chunk of the lip missing, must have had quite a whack!
Everything worked perfectly.

I'd file this under "if it ain't broke don't fix it."

My 500mm F4.5 had the same thing, never effected the image quality or the mounting of the hood.

As far as I am concerned only bad things could happen by "fixing" it.

I think it would definitely affect resale value. To me it says drop or hard knock, and who knows what alignment issues that can cause. A lens that expensive, what's a few hundred to fix? While I realize it's not the same, I dropped years back my then new 1DsMKIII. It cost eight grand when I bought it new. It then cost over 600 to repair. Less than ten percent of the value at the time.

Having never had anything repaired by Canon, Is there a way to possibly email them the picture of the damage and at least get a ballpark repair estimate? Obviously if there were further focus issues etc. they can't predict that which I understand would affect the final price.

of course they "could," but they won't.

I wouldn't even worry about fixing the bent part until you ready to sell it, if there's alignment/focusing issue sure. Say you spend the money/time to straighten out something that effect the lens from doing it's job, then sometime down the line you bend it again only at this time you want to sell it.

I'd be leaving it alone also, especially if there isn't any optical issues with the lens. It's not as though you needed to straighten it out to fit a filter on it or anything (like my 16-35mm needed after tripod fell over on concrete - but that's another story... )

link to parts catalog to see how it goes together: http://www.f20c.com …20600%204.0%20L​%20USM.PDF

If all else fails, check with someone that does auto body work. They probably have the
tools, and skills, to bend it back close to it's original shape without too much effort.

--Evan