focus 'whirling' noise on 15-85 lense
I just have a bit of spare time on my hands so thought I'd seek opinion before I get busy again..
I've been noticing some 'whirling' noise on my Canon 15-85mm IS USM lense recently when focusing and don't recall whether it made that noise when it was new so I'd just like to check with everyone whether this is normal. When I hold the down the shutter button half way I hear the quick and prompt focus lock, and continually hear this whirling noise for as long as I hold the shutter button half way. If I let go of the button then the whirling noise subsides as if there's something in the lense that was spinning that has stopped (like when you have a CD spinning in your laptop and you click eject the whirling sound will quickly come to a stop after a second or two). Is this part of the USM sound that I just didn't notice back when it was new?
Note this was all heard when I'm in a quiet environment and while holding the camera to my eyes. The lense is approx 10 months old.