Tamron 70-300mm F/4.5-6.3 Di III RXD (Model A047) Tamron has announced the launch of its first lens for Nikon Z mount mirrorless, the Tamron 70-300mm F/4.5-6.3 Di III RXD, positioned as the “world’s smallest and lightest telephoto zoom for full-frame mirrorless.” At 5.8 inches in length and weighing 1.28 pounds, it does compare favorably to Nikon’s closest equivalent, the NIKKOR Z 70-200mm f/2.8 VR S, which weighs 3 pounds and measures 8.7 inches long. Though the Nikon lens offers a faster and constant maximum aperture of ƒ/2.8 while the new Tamron is slower and has a variable maximum aperture, the Tamron is priced at just $699—$2,000 less than the Nikon. The Tamron 70-300mm F/4.5-6.3 Di III RXD has a minimum focusing...