Sony Ultra Wide Converter 0.75x for E 16mm f2.8The Sony Ultra Wide Converter 0. 75x (model VCL ECU1) is designed for use with Sony's E 16mm f2. 8 lens, providing an image equivalent to a 12mm lens (~18mm full frame equivalent). It's a noticeable difference, and quality is good. Please keep in mind that this is just an accessory lens, and it requires the Sony E 16mm f2. 8 lens to work. It is not compatible with other lenses and will not do anything on its own. Do not buy this if you do not have a