This new lens uses XR (Extra Refractive Index) glass to reduce the optical length of the lens through high refractivity. At the same time reducing the number of elements results in a more compact, lightweight lens package. In addition to XR glass, three hybrid aspherical elements and two high grade LD (Low Dispersion) glass elements have been incorporated to reduce all types of aberrations. With a filter size of just 62mm, maximum diameter of 73mm, length 83.7mm and weight of 420g, the Tamron 28-300mm XR Ultra Zoom lens is the world's smallest, most lightweight in its class.*
The 28-300 XR also achieves a minimum object distance of 49cm at any zoom setting, with maximum magnification ratio of 1:2.9. Even at the 300mm telephoto setting the lens can faithfully capture an area about the size of an audio cassette tape: 6.9x10.4cm.