Canon 28-135mm Problem

[vaydehi_khandelwal]

My 28-135mm lens has stopped focusing on auto focus!

As i am at the back of beyond, i dont have access to any Canon Service Centers. 

Please give suggestions as to how this problem can be solved.

Its been affecting my work tremendously as i need to quickly capture moments.... 

Thanks

Vaydehi.k

[cabbiinc]

<p>Well lets start with the basics.</p>

<p>1) make sure that you have AF enabled on the lens, also make sure that you have the correct AF mode selected on the camera. One shot is what I normally use.<br>

2) make sure that you have something worth focusing on. If the camera can't see any contrast it may not even try to focus.<br>

3) clean the contacts between the lens and the body. Make sure that you don't introduce dirt into your camera body. Rubbing alcohol and a Q-tip may be just the thing, just make sure you don't add another problem trying to solve this one.<br>

4) try different modes on the camera body. Full auto mode if you have it. If your camera works in full auto but not in another mode then look into the custom functions of your camera.</p>

<p>Other than those things I can't think of anything else. If you have another camera try that lens on it.</p>

[kasperhettinga]

<p>Few questions which may help:<br>

-as Dan suggested, first check the lens (is the swith set to AF) and the camera (easiest for now is setting it to Auto=green square)<br>

Then:<br>

-does the green circle in the bottom right of the viewfinder blink, or is it on or off?<br>

-do you see/hear the lens focusing (also look at the distance window on top of the lens - the sound is minimal for an USM lens)?<br>

-did you try the body with another lens?<br>

-did you try the lens with another body?<br>

-can you use manual focussing over the whole range of distances?</p>

[janet_forsythe]

<p>i had that problem with that lens and the IS mechanism had to be replaced.<br>

mine started when i look a photo with the lens pointing down it wouldn't focus then progressed to where it wouldn't take a photo at all no matter what the position of the lens( wouldn't allow me to completely depress the shutter cause it never would focus)<br>

they had to replace the mechanism twice, after the first time it still didn't work. what about a third party repair place? I've use KEH successfully. they will examine it for free then send an estimate.</p>

[steve_dunn2]

<p>In addition to just looking at the AF/MF switch to make sure it's set to AF, move the switch. Set it to MF, then set it back to AF. If the contacts are getting a bit bad, or if it the switch somehow got jiggled slightly, it might look like it's in AF mode but it may not actually be, and flipping it to MF and back may resolve the issue. (If your unnamed body's LCD panel displays whether the lens is in AF or MF mode, as mine does, also have a look at that to make sure the body agrees with what you think the switch says.)</p>