24-70/2.8L USM Focusing Noise

<p>Hi All,<br>

I just managed to get my hands on a 24-70/2.8L which is my first USM lens. I was under the impression that focus was completely silent. However, during focus I can hear some movement which is readily audible albeit nowhere near the same scale as the non USM lenses. I assume that the movement I can hear are the internal elements moving about? I ask as I do not want to return a lens when it is perfectly fine!<br>

Thanks for your help,<br>

James</p>

<p>I never really paid much attention to the noise, so I just mounted it on my 7D and listened closely. I can hear a very muted "sliding" type of noise as it focuses. It is quite audible while I'm holding it, but I don't think it would bother anyone sitting near me. A few seats further away and it would have to be really quiet for you to hear it well.</p>

<p>My 24-105L is very quiet, but I wouldn't call it silent. Someone sitting next to me wouldn't hear it unless it was dead silent in the room. You can hear the internal movements if you put it close to your ear, but there really isn't a whirring motor noise or anything like that. While some come may close, I don't believe there is such a thing as a truly silent DSLR AF lens unless it's focused manually.</p>

<p>Like Randall's my 24-105L is very quiet on a Canon 5D. It is even quieter when the IS is switched off. My 70-200L which is non-IS is virtually silent and focuses almost immediately. I doubt whether anyone could hear it even in a quiet room.</p>

<p>My 24-105 is also very quiet but my 24-70, a totally different lens, is not. In quiet places (think church between hymns) I can hear the lens focusing, esp. when drastically changing the focus plane from WA up to circa 50 mm focal lens. (IMO it is so because the lens extends at WA settings and the noise becomes more audiable, less muted by the lens enclosure.) It is hard to say whether it is normal or not because another sample of that lens I was using was almost dead quiet at all focal lengths (but both samples seem to be equal in terms of IQ.) I'd say that if you can hear the lens focusing in "average ambient noise environments", consider sending it in for service.</p>

<p>Seems to be normal. <br>

Same here (EF 24-70 f2,8L). But only in a very silent room...<br />and if it is 3ft away I doubt you will still hear much. <br />Bleep for in focus is much, much louder at that point</p>

<p>The motor itself makes its sound at a frequency too high for humans to hear, but any time you have moving parts, there's a potential for sound to be generated as they move. I don't have the 24-70 but I have four USM lenses (and have had a few others in the past) and they all make a bit of sound when focusing. Indeed, I just tried manually focusing two of them (24-105 and 17-55), and they sound very much like they do when autofocusing.</p>

<p>The motor is silent--unless you're a dog--but the mechanical movement of elements make a pianissimo "rolling" sound. Reminds me of plastic wheels on concrete but is inaudible save for a very silent room.</p>

<p>The 24-70 is a fairly silent auto focuser -- my quietest lens is the superb 85mm 1.8.</p>

<p>I could hardly hear mine and I used it in desolate wild-life refuge parks at dusk. </p>

My findings are the same as Ken's. All IS systems are noisy when active and all lenses have AF noise - either my

Sigma 8mm F3.5 fisheye or my Canon 15mm F2.8 being the worst. That said I would only find AF noise an issue if I

was shooting video with the on camera mikes. I also find that my 70-200 F4 LIS has the noisiest IS system of any of

my lenses

<p>Thanks for all of your comments. I have compared it to a friends 35/1.4L and the level of audible noise appears to be the same.</p>