I have an EOS3 and a 28-135 IS Canon lens (new and under warranty).

When the AF setting on the lens is chosen, the camera and lens work fine. But when I try to use the MF (set on the lens), and turn either the lens ring/dial or the macro ring/dial, it seems as if the lens is "locked" (the dials do not want to turn).

Can someone please advise? Thanks

-- J P de Kock (jpdekock@uumail.de), September 22, 2001

Answers

What do you mean by "lens ring/dial" and "macro ring/dial"? On the lens there is the zoom ring and the focus ring. Is that what you mean?

When turning the zoom ring (the wide ring closest to the front element), you should be able to turn it from the 28mm position to the 135mm position. Look at 28.35.50.70.100.135 markings on the zoom ring as you do so. Obviously you can't turn it past 28 or 135. You should also observe the lens zoom in or out as you do so. If you are unable to do any of this then there is definitely something wrong with your lens. Of course you should be able to do this in both AF and MF.

When turning the focus ring (the narrow ring closest to the camera body) you should be able to turn it from closest focus (macro) to farthest focus (infinity). Look at the focus scale in the clear window. You should still be able to turn the focus ring even though the scale is stopped at macro or infinity, although you will feel more resistance from the ring. Again, you should be able to do this both in AF and MF. If you can't do this, then there is definitely something wrong with the lens.

The zoom ring drives a helical that telescopes the lens in and out. There is no reason it should be locked. The focus ring (as with all Canon ring-USM lenses) does not have a "mechanical" coupling like gears and teeth locking together as in other manufacturer's lenses. So there is no reason it should be locked either.

-- Peter Phan (pphan01@hotmail.com), September 22, 2001.

Thanks so much for the time you took in your response.

Yes, I meant the focus ring. When you set the AF/MF switch on the lens to either AF or MF (Manual Focus), you should be able to turn the focus ring.

You won't believe what I did after reading your mail. I "applied" a bit of pressure (quite a bit, I must say) when turing the focus ring, I heard a pop, and the resistance gave way. It now works!

I hope to hell I have not damaged the bloody lens. I gave it a shake, tested the focus ring a few times, and all seems OK. Perhaps it only needed more use, and due to the lack of it, became bogged down with some fine grime.

Oh well, time will tell if I did bust it!

Thanks again for your help. What possible benefit is there for you to hand out such detailed and sound advice???? I'm curious.

Thanks again.

-- JP de Kock (jpdekock@uumail.de), September 22, 2001.

You get complete and expert answers on this site because it's full of nice guys who love to talk about photography! Often no one at home or work gives a hoot about photography (my wife told me not to bring the topic up anymore as it's boring), so helping strangers that share your interest is a way of sharing your hobby (& maybe helping make the world a slightly better place). If you're really hungry for EOS 3 discussions, you can join the EOS 3 Email list:

http://www.egroups.com/ group/eos3/

-- Puppy Face (doggieface@aol.com), September 22, 2001.