I received this Tamron SP 70-300mm f/4-5.6 Di VC USD lens last week and took several pictures using a 5D and a 1D Mark II and I really like the results. But I do have a question for other owners of this lens…or maybe any other Tamron VC lens owners. I noticed what feels like a strange jiggling towards the rear of the lens where it mounts to the camera body—around the area where the “VC” is printed on the exterior of the lens. There is no rattling or any sound at all, so I don’t think it’s anything that has broken off inside the lens. The images I have taken look fine and the VC seems to work as it should so I figured that the jiggling is just some sort of moving element(s) used by the VC system. I tried to see if my 70-200 IS had the same sensation when handling the lens, and I did not feel anything. So now this concerns me.
So for those who own this lens, when you hold the lens in your hand and rotate your hand like you’re twisting a door knob, or while gripping the lens, just gently wiggle your lens back-and-forth, do you feel something inside the lens jiggling around? Or is this normal? Jiggling is the only word I can think of at the moment because it definitely feels like something is being suspended inside the barrel of the lens and it’s just moving around.
This is the first VC lens I have gotten, so I don’t know if this quality is normal, especially since my Canon lens with IS does seem to exhibit the same qualities. 
