Image of the Tamron SP 15-30mm F/2.8 Di VC USD split in half.

Image courtesy: DC.watch.

Usually you don’t see how a lens is made “inside”. But at CP+ Tamron is showing the new SP 15-30mm lens cut in half. There is also a full review at Photoreview:

Outdoor photographers will welcome the moisture-resistant construction of this lens as well as the fluorine coating on the front element that repels water and dirt and makes it easy to keep clean. Architectural photographers will find relatively low distortion produced by this lens valuable for shooting exteriors and interiors. 
In summary: Photographers looking for a fast, wide-angle zoom lens will find this lens represents excellent value for money. 

The A-mount lens can be ordered at BHphoto (Click here) and at Adorama (Click here).