Introduction Available in versions dedicated to Nikon, Canon and Sony, the Tamron SP 70-200mm f2.8 Di VC USD contains 23 elements in 17 groups. Four of the elements are low dispersion glass (LD) and one is extra low dispersion (XLD). The aperture is constant throughout the range. The name of the lens includes 9 letters indicating various features of the design: SP refers to Super Performance: Tamron’s premium range of optics. Di is “Digitally Integrated Design”, VC is “Vibration Compensation” (not present in the Sony version, since the Sony cameras have IS built in), and finally