Canon 70-200 2.8L focusing problem

[chito_baclig]

Hi all,

 

RE: EOS 3, Canon 70-200 2.8L focusing problem. Here is the problem.

My subject is about 5 meters as indicated in the lens distance

settings. If I set the focusing ring to read 10 meters and press the

shutter halfway, it will focus. But if I set the focusing ring to 1

meter and press halfway, the lens motor seem to work but only get to

about 3 meters. If I keep pressing the shutter halfway, I sense that

the lens seem to be trying but still won't focus. Is there a way to

fix this? Or time to take it to Canon service center.

 

Regards to all.

[stephane camus]

Hi... well, I am sure you have been looking at this, but did you check the focus limit switch?

Do you experience the same problem with the switch on the different position?

I tried to reproduce your problem with my EOS3 and 70-200mm f4 and it worked fine. The focus limitation switch has two position on this lens, 1,2m to Infinity and 3m to Infinity, maybe there are different settings on the 2.8 version.

Good Luck!

Steph-

[chito_baclig]

I should have mentioned it. Yes I did check the focus limit switch.

[marc schneider dc metro]

The only time I've seen something like this is when the focus limit switch is set to 3m - infinity. If the lens is focused closer than 3m when you throw the switch, the lens won't focus past 3m.

[chito_baclig]

Actually it does focus. The only thing I must do is to rotate the focusing ring to about 10 meters if the subject is about 5 meters. This is the workaround.

[brett_bainbridge]

But that's exactly what Marc just said... when the initial focus is within the 3M range and the limiter switch is thrown, the lens loses the ability to autofocus out past that 3M limit... hence when you manually focus out to 10M then begin autofocusing, it's no longer limited and can do its work normally.

[chito_baclig]

Let me repeat, my subject is (more than) 5 meters. That means, if I rotate the focusing ring to read 1 meter (making the subject out of focus), its should autofocus the subject, but for some reason the motor moves upto the 3 meter mark and stops.

 

Again, that is not true if I rotate the focusing ring to 10 meters (or infinity).

[stephane camus]

Hello again.

Well, I had the opportunity to play with an EOS 3 mounted with a 70-200mm f2.8 today, at Yodobashi (this is my last days in Japan, so I go shopping!).

I can reproduce a similar problem than the one you describe.

Here is what I did.

I focused on a subject, 5 meters away.

I turned manually the focusing ring to 1.5m

I tried to refocus...

nothing happened.

So I started moving the focusing ring and it is only at almost 3m that i reacted again and refocused on the subject, 5 meters away.

Now, this is the irritating part -and I swear it is the last time I mention this ;) - it works fine if the focus switch is set on 1.5m to infinity. So in this case, the problem only occurs when this switch is on 3m to infinity, which is, in my opinion, a minor problem, if not logical.

So the thing I found does not seem as extrem as what you describe, but it looks a little bit like it.

This makes me wonder if your lens might have some sort of calibration problem.

The things I would try...

-Try on a different body to see what happens. Could be a problem coming from your eos3 body.

-Check the lens & camera contacts and clean them.

-Go and see a retailer for a side by side comparison with another 70-200mm f2.8

Good luck!

Steph-