IS question on Canon 100-400L

When I carry my 100-400, particularly if it's tilted down and most especially if it's fully extended, I can hear and feel what I presume to be the IS system rolling and clunking around inside. The lens is sharp and functions properly otherwise, I'm just curious if I should feel that IS motor moving inside while simply walking (I'd understand if I was in a full-out sprint down the road with it).

It's still under warranty and if it's behaving improperly, I suppose I should get it taken care of. Like I said, it performs well otherwise and maybe that's just normal for this lens.

Thanks in advance for any answers or opinions.

Mine does not do this.

Not something I have ever noticed with mine.

Neil

Lowner wrote in post #15120313
Mine does not do this.

Mine neither.

Great. Alright, I'll contact Canon customer service then and see what's up. I'm a bit miffed because the lens is pretty sharp and I'm not sure that I want it swapped out but I surely don't want a broken lens either. Thanks for the responses all.

I might be off base with this suggestion, however I noticed after replacing my 70-200f/4 with a 70-200f/2.8 a light "clunking" when moving with the camera around the neck on the strap. Traced it to a very slight amount of movement between the lens and the body at the mount (not lateral, but as if to try and remove without depressing the release button). This seems to be magnified when walking/moving with the camera slung around the neck by the strap. My 15-85 f/3.5-5.6 has the same amount of slight movement, but thinking the length is substantially shorter and lighter, this movement isn't telegraphed through the lens body as much as the larger lens. Is this slight "slack" at the lens to body mount normal?

Try the lens lock, see if that makes any difference. -rick

I have never noticed this, either. Rick's recommendation seems worth a try, though. If you do send it in to Canon, please let us know the result.

Julius

BigLobowski wrote in post #15121740
I might be off base with this suggestion, however I noticed after replacing my 70-200f/4 with a 70-200f/2.8 a light "clunking" when moving with the camera around the neck on the strap. Traced it to a very slight amount of movement between the lens and the body at the mount (not lateral, but as if to try and remove without depressing the release button). This seems to be magnified when walking/moving with the camera slung around the neck by the strap. My 15-85 f/3.5-5.6 has the same amount of slight movement, but thinking the length is substantially shorter and lighter, this movement isn't telegraphed through the lens body as much as the larger lens. Is this slight "slack" at the lens to body mount normal?

I don't know the answer to that questionf. I have a 15-85 and have never noticed anything like this. With the 100-400, I THINK that if I keep the tension ring tight and the lens fully retracted that the sensation or noise goes away. I already contacted Canon customer service by email and they didn't seem to have an answer and they seemed perplexed by my situation but they offered to take a look at it. I'm going to take some time with it today to see if maybe it's my imagination but if it's something that they've not encountered before, I don't want to be messing with it.

Something else struck me as odd too. I was reading the warranty and I get the impression that they're only required to fix or replace with a refurb if something is broken. Since I purchased the lens new less than two months ago (not a refurb), I'm not sure why I'm not entitled to a new lens, if in fact something's seriously wrong with this one.