The new Tamron 20-40mm f/2.8 Di III VXD is one of the more interesting lenses to come along in a while, offering an intriguing focal length range that sacrifices reach at the long end compared to a 24-70mm for the ability to go wider than the usual 24mm, putting it somewhere between a standard zoom and an ultra-wide angle zoom. This excellent video review takes a look at the lens and the sort of performance and image quality you can expect from it in usage.