I know the D3000 wants an AF-S lens. This Tamron does not say it is AF-S, but does say it has a focus motor in it. Would the autofocus on this work on a D3000? This is the first time I am trying a non-Nikkor lens. Amazon.com: Tamron AF 18-200mm f/3.5-6.3 XR Di II LD Aspherical (IF) Macro Zoom Lens with Built In Motor for Nikon Digital SLR: Camera & Photo Thanks in advance!