Sony Carl Zeiss Sonnar T* FE 55mm F1.8 ZA (SEL55F18Z)A perfect pairing for full frame Sony E mount cameras, the Sonnar T* FE 55mm f 1. 8 ZA Lens offers excellent resolution and a bright f 1. 8 aperture for photographers looking for a high performing normal length prime. Based on the ZEISS Sonnar optical concept, this lens uses a design with seven elements in five groups that helps achieve the large maximum aperture of f 1. 8 while simultaneously reducing flare and improving contrast.