This Tamron lens is a classic telephoto zoom for Sony E-mount mirrorless cameras, with a large aperture of f/2.8. It delivers excellent sharpness and contrast across the frame at all focal lengths, even wide open. It also boasts weather-resistant construction, using lightweight yet durable materials. The optical design exploits several special elements and coatings, while a floating focus system ensures crisp and sharp images, even at close subject distances. With a very quiet but responsive autofocus mechanism, this lens is a bargain in its class, both for photography and video.