Tamron has developed what it is calling the “the world’s first ultra-telephoto zoom lens.” The F3.5-6.3 Di II VC HLD lens gives range of 18-400mm and has 22.2x .This amazing zoom ratio is made possible by a newly developed moisture-resistant lens barrel design which utilizes three-step extensions. Tamron says the "larger number of cams ensures comfortable operation and stability while zooming." It boasts a minimum focusing distance of 17.7in (0.45cm) and maximum magnification ratio of 1:2.9.
Image source : peta pixel
