100L focus issue - please advise

[tdigi]

<p>I just got my 100L macro and I notice often it does some strange things when I try to focus that my old macro lens did not do.<br /> <br /> I try to focus on something about a foot or so away, it will go back and forth very quickly and then when it says I am in focus all i see is a blur. Sometimes my old macro would go slowly through the focus range when I shot macro but this one does it very fast and then just beeps even though its focused on nothing. It does it pretty often.<br /> <br /> It also seems to hunt much more then my old macro lens did. Its very sharp when it actually focuses, but something seems wrong.</p>

<p>Also the IS on this makes a much different sound then my 24-105. Probably normal but I thought I would mention it.</p>

[bob_mcbob]

<p>The only time I have focus problems with my 100L is when I accidentally have the focus limiter set from a previous session.</p>

[tdigi]

<p>I have it set to full. </p>

[mbkissel]

<p>That does not match my experience, Tommy. Mine does not "hunt" at all in anything considered decent light, and very little in poor light. In very, very dim light, it may go through the range and quit, but I never get the focus lock beep in those situations.</p>

<p>I don't have a 24-105, so I don't have a point of reference. The IS does sound a bit different than some of my other lenses, but it's very quiet. I have to put my ear close to the lens barrel to hear it.</p>

[jim_j2]

<p>Tommy,<br>

When I first acquired my 100L Macro I noticed it seemed to "Hunt" considerably for focus. Most of the time I found that I had the IS switch set to the wrong distance setting, but yes when set to "full" it seems to have to have a little "manual focus" help sometimes. Especially for closeup or Macro focusing. Seems to focus at distances beyond 5 feet immediately.</p>

<p>Maybe I've just gotten more used to the lens, but I don't seem to have the problems that I did the first few days I had the lens.</p>

<p>Yes, the IS sounds different than the IS on my 100-400L and does not appear (through the Viewfinder) to be working as strong as the IS on the 100-400.<br>

I have three of Canons IS lenses. They all react and sound a little different when compared to each other. But the end result is the same.</p>

<p>I don't think your lens has any problems IMHO.</p>

[paddler4]

<p>Mine has no focusing problems at all, but then again, I usually use the focus limiter rather than leaving it set to "full." There is a reason it is there.</p>

<p>The IS ought to sound different. It is a different mechanical mechanism. this is the only canon lens with hybrid IS, I believe. But the proof is in the pudding. If it works, it works.</p>

[tdigi]

<p>But if I manually focus it close as soon as I hit the autofocus it goes right back to hunting and then locks focus on nothing, just a blur. Its going back.</p>

[philip_wilson]

<p>Sorry for the delay in responding - I was travelling. I think you might have a dud. Mine works fine on any of my EOS bodies - I generally keep it in either the macro or non-macro range - not full as i find it focuses faster. That said the lens in normal range is actually quite fast focusing. It does not focus as fast as a more sports oriented lens like the 70-200 f2.8 or 300 f2.8 / F4 but it is faster than a lens like the 50 f1.4. I cannot recall any hunting problems with this lens in normal ranges - except in very poor light with extremely low contrast targets (like a white wall). In macro mode it can take a short time to focus but not unreasonable given the lens movement.</p>

[tdigi]

<p>What's really strange is it claims its in focus so I get the beep but in reality its just a blur. I may be wrong about it being a dud because I tried shooting this same chart with a different lens and had a somewhat similar result. I rarely shoot test charts so maybe I am doing something wrong but is that not strange for a lens to claim focus when its showing nothing but a blur? I have been pretty busy so I am going to try and test it out again tonight but I am now suspecting the lens is fine. I did find the macro would go all the way back and forth through the range on occasion but I seem to remember my old macro doing that as well.</p>