Lens hood is stuck!

The lens hood on my 500mm/f4 IS stuck. The set screws that tightens the hood on the lens must be lose and needs tightening. Does anyone know what size set screw is used or any other solution?

Thanks

sagebrush wrote in post #11323263
The lens hood on my 500mm/f4 IS stuck. The set screws that tightens the hood on the lens must be lose and needs tightening. Does anyone know what size set screw is used or any other solution?

Thanks

Is the knob off.....?

No the knob is still on. I backed it off all the way but is still engaged on the lens.

sagebrush wrote in post #11323762
No the knob is still on. I backed it off all the way but is still engaged on the lens.

Just take a hammer to it, or buy a new one. Its not like its a good lens or anything...

Sorry, im not being productive. Good luck.

Red Tie Photography wrote in post #11323793
Just take a hammer to it, or buy a new one. Its not like its a good lens or anything...

Sorry, im not being productive. Good luck.

Yeah, that's a $500 hood there.....

For the OP, try to use a rubber mallet (some heavy object wrapped with a towel) to hit on the knob. Maybe having the lens point upward while you are holding it sitting down?? The hood inner ridge isn't round. More like a horse shoe shape. When you tightened it, it pulls towards you. When you loosened it, it gets pull away from you. I don't believe the knob has been disengaged from the locking tab. Use a flash light to look from the front element. It should move up and down as you loosen/tighten the knob.

Exactly like you said...while sitting down and pointing the knob upward I shined a light inside the hood. Then watched the little tab retract upward while I turned the knob and the hood is FREE.

There is something definitely wrong here!

Anyway thanks for your patience and help.

TooManyShots wrote in post #11323861
Yeah, that's a $500 hood there.....

For the OP, try to use a rubber mallet (some heavy object wrapped with a towel) to hit on the knob. Maybe having the lens point upward while you are holding it sitting down?? The hood inner ridge isn't round. More like a horse shoe shape. When you tightened it, it pulls towards you. When you loosened it, it gets pull away from you. I don't believe the knob has been disengaged from the locking tab. Use a flash light to look from the front element. It should move up and down as you loosen/tighten the knob.

Just to simplify things, my idea of taking a hammer to it was somewhat close? You even said take a hammer (like object) to it.

Win? I think so.

Sure you need to take the hood off? I never have.

I just had my lens hood stick. First time in the 1 1/2 years I have owned it. I am the original owner. To make a very long story short, after talking to Canon tech support thye recommended pushing out the roll pin that holds the nob on to expose the threaded screw that goes though the T. They thought the screw would then come out. WRONG! There is the wedge that tightens the hood to the lens, and the wedge should be loosely connected to the threaded screw by a snap ring or E clip. Turns out the snap ring was missing and the wedge had been held in place to the hood by a small piece of fiberglass tape. So the wedge would move up and down because the tape was flexible, but finally it became stuck.

After unscrewing the threaded screw until I met resistance, I then used some small tools to lever the wedge away from the lens and then was able to remove the hood without any damage to the hood or lens. The repair would require a tiny snap ring that probably costs ten cents. The piece is on its way to Canon Irvine; they have indicated they will probably replace it without charge after they have had a chance to look at it.

This happened to me with my 500 f4. The little flat piece that fits in the groove on the lens came loose from the set screw. I had to get a very small screw driver and take the hood apart in order to get it off of the lens. I called Canon and they said to send it to them, I sent them just the hood and I got it back exactly one week later with a new set screw assembly in it. It was the same hood as I could see where I had taken it apart to get it off.
By the way my lens was brand new when this happen, first time that I tried to use it after unpacking it. Have not had any problems since then.

Bob