Jun 19 2005: The first 3 pictures are of the Tamron "SP Pro" 2xTC and the Quantaray 2xTC. The fourth image is what you can generally expect from the Tamron 1.4xTC (non-Pro version) and the Quantaray 2xTC. The fifth image is a quick test of the Kenko "Pro 300" 2xTC and the Quantaray 2xTC. NOTE: The Kenko "Pro 300" and the Tamron "SP Pro" are IDENTICAL teleconverters both in build and optical performance. I'm of the opinion they are probably made by the same manufacturer. They are EXCELLENT, professional alternatives to the Canon EF teleconverters. See this recent test between the two "Pro" TCs at http://www.pbase.com/lightrules/2xtcs