I have a Sigma 17-70 F2.8-4 OS HSM and it is awesome.. never had problems.
My friend has one as well, using it with a T4i.
This is what he described:
- Was working great for the 2 years he owned it
- Suddenly there was problems with it out of no where, it was never dropped etc.
- Whether the camera was on manual or auto mode, there is usually a constant vibration sound coming within the lens
- The result is it twitches, when holding it steadily taking pictures or recording a video, it has these twitching vibrations causing shake resulting in shaky video or photos.
I checked it out myself and what I noticed it the lens has this slight vibration sound coming from the inside, not constant but almost all the time. I only changed between auto and manual focus, maybe it could be something to do with the image stabilization feature, or something inside the lens became loose ?
Anyone know what could a common problem and is it repairable