70-200 Manual focus ring broken.

So i just got my 5dMKII , very exciting! Except that when i went to manually focus with my 70-200 2.8 i noticed a problem. Sometimes when turning the ring it wouldnt alter the focus, sometimes it would start ok then stop.

Auto focus works fine, and focus using the af-on button work no problem. This is how I always use this lens so i wander how long it has been broken. Theres no reason for me to have noticed this before. It seems that whatever mechanism is beneath the rubber focus ring, it is not gripping whatever it needs too inside the lens in order to focus. Sometime is grips and you can feel it working then it will just slip, just like when you continue to turn the ring at either end of the focal range.

Has anyone else ever had this problem? Did you get it fixed , how much?

thanks!

dandig wrote in post #6809558
So i just got my 5dMKII , very exciting! Except that when i went to manually focus with my 70-200 2.8 i noticed a problem. Sometimes when turning the ring it wouldnt alter the focus, sometimes it would start ok then stop.

Auto focus works fine, and focus using the af-on button work no problem. This is how I always use this lens so i wander how long it has been broken. Theres no reason for me to have noticed this before. It seems that whatever mechanism is beneath the rubber focus ring, it is not gripping whatever it needs too inside the lens in order to focus. Sometime is grips and you can feel it working then it will just slip, just like when you continue to turn the ring at either end of the focal range.

Has anyone else ever had this problem? Did you get it fixed , how much?

thanks!

It sounds like what happens if the camera is not in one-shot focus mode. If you have it on Ai-servo and you try to manually adjust the focus the camera will think the item your pointed at has moved and it will fight you for control of the focusing.

Put your camera on one-shot focus mode and i'm sure you will discover your lens is fine

Is the focus still not turning even when the camera is off, or the lens detached?

I bought a secondhand 70-200 f/4L IS and it wouldn't focus back from infinity when pointing up, and it was very sketchy when horizontal. I took it to Canon, and they said it would cost up to AUD$300 to get fixed. It's still in the shop now, so i'll let you know how it turned out

i had something similar happen to my 28-70 2.8
sent it to canon to get the whole a/f mechanism replaced
$150 and a few weeks later .. the af was like new

they even sent me the replaced part!

Sadly thats not the case, I had it in one shot and ive tried it on 2 different cameras and also when its not on the camera.

Thats interesting, don't know how i can live without the lens for a few weeks though !

Same thing happened on my 400 L f/5.6 last week. Only noticed it when I was actually at my dealer, so a quick substitution with a 300mm and mine is off for repair. Hope the dealer sticks to his secondhand warranty ! But I like this 300mm as well.