The Tamron 11-20mm F/2.8 Di III-A2 RXD Lens is a quick-aperture ultra-wide zoom lens made for APS-C mirrorless cameras with a Sony E mount. It boasts a fast and continuous f/2.8 maximum aperture, all while being compact and lightweight. This lens is ideal for capturing landscapes, stars, and architecture. Its bright f/2.8 aperture adds to the usefulness of this range, providing more control over depth of field and improved low-light capability. The lens design includes an XLD element, two LD elements, and two glass-molded aspherical elements to deliver a well-corrected image with minimized chromatic aberrations and color fringing, enhancing clarity and color fidelity. Each element has Tamron's BBAR coating that reduces flare and ghosting for improved contrast when working in harsh lighting environments. The RXD stepping drive motor provides fast, nearly silent autofocus for both still photos and videos. It has a minimum object distance of just 5.9 inches at the widest zoom, allowing for powerful wide-angle macro shooting with a unique perspective. Also, the f/2.8 maximum aperture offers a shallow depth of field resulting in soft bokeh background details. Moisture-resistant construction protects the lens in tough conditions, and the front lens element has a fluorine coating to guard against dust and smudges. This adaptable ultra-wide zoom is perfect for Sony E-mount APS-C-format mirrorless cameras, offering a 35mm equivalent focal length range of 16.5-30mm. A constant f/2.8 maximum aperture ensures a consistent brightness across the zoom range, improving depth of field control. The XLD, LD, and GM elements significantly minimize color fringing, chromatic aberrations, and distortion for better clarity and color fidelity throughout the zoom range. Tamron's BBAR-G2 Coating is applied to suppress reflections, glare, and ghosting, resulting in greater contrast and color accuracy. The RXD autofocus motor provides quiet, fast, and smooth focusing suited for photography and video. With a minimal focus distance of 5.9 inches at 11mm, it explores dynamic wide-angle macro imagery, making close objects appear larger and distant objects smaller. Additionally, using the f/2.8 maximum aperture gives a shallow depth of field with soft bokeh. Designed and built to be moisture-resistant for harsh conditions, the front lens element has a fluorine coating to protect against dust, dirt, and smears. A rounded seven-blade diaphragm adds to an attractive bokeh quality.