It has been a "while" since I've used my 24-105 and I have forgotten if the following is normal or an indication of trouble,
If the IS engages it produces a gentle purr, as I seem to remember it did when it was new, however if I change the focal length during IS operation it starts making more noise, almost "grinding" like. This only happens if IS is functioning and the focal length is changed, which I don't do very often as I am more likely to set focal length before engaging AF and IS. Now compared to the 100-400 or 70-200/2.8 IS it is still pretty descent, but requiring minds need to know. Have I simply forgotten the noise, or might this be an indication of trouble?
Hi Ruy, I just tried mine. I might hear what you describe, but it's not very pronounced - I wouldn't describe it as anything like grinding. It seems to get a bit louder at the lens increases in length, perhaps as there's more internal volume that allows the sound to resonate a bit. It's not a very obvious change in sound though. It's completely masked by the fan noise on my PC (it has big fans). I had to find a quieter room to hear it. Jim.
Mines very quiet. almost have to hold it upto my ear to tell if its working. the 2 othe IS lenses I've used are/were much more noticeable 100-400L & 70-300 is (that ones pretty noisy)
Ian, let me emphasise that it only makes this noise if I zoom the lens in or out while the IS system is engaged, otherwise the IS operation is the most silent of my three IS lenses.
Jim & Tim, well it is soft grinding-like for lack of a better word. Perhaps it would be better to say that the character of the IS sound has a distinct change once I move the zoom backwards or forwards while it is in operation. Whereas the normal sound is a soft purr, the changed sound is more pronounced and reminds me a little of grinding coffee beans.
The silly thing is that I really don't remember if it ever did so before. I remember the soft sound, but not the change. The lens has recently been calibrated and shipped back and fro, so there might be a reason why things may (or may not) have changed. In terms of performance I have seen no detrimental effects.
