A true marvel of portability and utility, the 70-180mm F/2.8 incorporates an innovative zoom mechanism and 180mm telephoto power. It was possible to maintain extreme light weight and compactness even while attaining a fast F/2.8 aperture across the entire zoom range by leveraging the camera-based image stabilization. It is small: filter diameter 67mm, maximum diameter 81mm, length 149mm (5.9 in) at the 70mm setting, and also light weight: 810g (28.6 oz). The super-compact size helps make handheld shooting a breeze. As part of our constant, ongoing effort to achieve both high image quality and supreme compactness, Tamron went to great lengths to create this product in answer to demands of the new generation of digital cameras.