The 17-35mm f/2.8-4 Di OSD (model a037) is an ultra-wide-angle lens featuring superb image quality integrated into a compact, lightweight body. The use of specialized glass materials enables comprehensive control of the axial chromatic aberrations conspicuous in ultra-wide-angle lenses. The model a037 offers a high level of sharpness and contrast comparable to the very best of lenses. From the 35mm standard wide-angle for user-friendly snapshot photography, to the ultra-wide-angle 17mm used for professional landscape photography, this lens can meet a wide variety of your needs and yet still offer amazing portability being only 90mm (3.5 in) in length, 83.6mm in diameter, and just 460G (16.2 oz.) in weight. With a minimum object distance (MOD) of only 0.28M (11 in), opening the aperture while approaching the subject lets you blur the background. Wide enough to encompass the entire landscape, the model a037 lets you capture the thrill of the moment in each and every image you shoot. The AF Drive employs newly developed OSD (optimized silent Drive) to ensure silent operation. The front surface of the Lens element is coated with a protective fluorine compound that is water and oil repellant. Leak-proof seals throughout the Lens barrel further protect the Lens when shooting outdoors. Compatible with Tamron's tap-in Console.