Tamron 28-200mm f/2.8-5.6 III RXD for Sony FE The Tamron 28-200mm f/2.8-5.6 III RXD for Sony FE is a powerful lens. As the world's first all-in-one zoom lens that can achieve a maximum aperture of f/2.8 at 28mm, it is sure to be a leader in the field and set the standard for future zoom lenses. Packed with impressive features, this lens is the perfect combination of speed, power and accuracy, guaranteeing top-notch results every time. The World’s First All-in-one Zoom Lens for Full-frame Mirrorless Cameras It has already been mentioned, but it is something that needs to be pointed out more than once. The lens offers the amazing ability to achieve f/2.8 at 28mm, the widest angle of the lens. On top of this, maximum apertures at intermediate zoom rages are f3.5 at 50mm, f/4.5 at 100.