The new Tamron 100-400mm f/4.5-6.3 Di VC USD lens now has an official $799 price tag, which is rather respectable given the zoom range. The lens is both lighter and smaller than I expected when I picked it up for the first time. I only spent a few minutes with it but I paid particular attention to the Vibration Compensation, which did a great job at the long end of 400mm even though it suffers from a slow f/6.3 minimum aperture. It provides enough stabilization to get you down to 1/60s at 400mm.
The long lens means there is definitely some air sucking happening as your rotate the zoom ring to extend or retract the zoom. You can actually feel air being pushed out of the lens behind the rear element when retracting it if detached from a camera. Tamron combats the threat of dust sucking with robust seals at the lens mount. Additionally, Tamron offers a generous 6 year warranty on its lenses, which covers dust inside the lens elements.
The new Tamron 100-400mm f/4.5-6.3 Di VC USD lens will ship on November 16 for $799. You can pre-order it here at B&H Photo.