In years past, supertele zooms— that is, lenses that start and end in the telephoto range, and reach to at least 400mm—were relatively rare beasts. Today, Nikon has a pair of excellent VR (image-stabilized) products, an 80–400mm and 200–400mm; Canon, a 100–400mm; Tamron, a 200–500mm; and Tokina, an 80–400mm. Last July, Sony unveiled a 70–400mm, which our test (September 2009) called "an optical superstar." It's Sigma, however, that dramatically ratcheted up interest in the supertele zoom, turning the category red hot virtually overnight. In a remarkable flurry of releases two years ago, it unveiled three at once: a 120–400mm, 150–500mm, and the Godzilla of all supertele zooms, the 35-pound, 28.6-inch, $29,000 200–500mm f/2.8.