My lens has gone schizoid

[tar heel]

<p>My Canon 70-200 2.8 IS on a 1D MKII yesterday was searching wildly for a focus. It was weird; the AF was searching in very short in-and-out motions, rhythmically... very quick and short movements looking for a focus. Subject matter provided plenty of contrast for a lock. Turn the camera off for several minutes and it works fine for a while, then starts it's weird AF thing again. Before I send it off to Canon, is there a quick fix anyone knows of I can try? I've done everything I can think of, and nothing would correct it. <br /> <br /> Conditions were very windy, lots of dust in the air... I tried cleaning both ends of the lens and nothing changed. I just thought maybe someone has had this happen and knows a solution short of sending it off.</p>

[anov]

<p>Sorry if it's obvious. You're not trying to focus nearby object with the focus limiter switch set to far-infinity aren't you?</p>

[PuppyDigs]

<blockquote>

<p>the AF was searching in very short in-and-out motions, rhythmically... very quick and short movements looking for a focus.</p>

</blockquote>

<p>Mah GF actually kinda likes that!<br>

AI servo by mistake or bump the focus limiter as N suggested?</p>

[tar heel]

<blockquote>

<p>You're not trying to focus nearby object with the focus limiter switch set to far-infinity aren't you?</p>

</blockquote>

<p>Cold have been, but I've done that before and never had that kind of reaction.</p>

[amol]

<p>Have you tested the the Camera Body with other lenses? Just to rule-out that it is a lens problem, not a camera-body problem?</p>

[tar heel]

<p>Great question, yes, it's only with the 70-200. Thanks! Should have mentioned that.</p>