The first of the series is the standard lens 30mm F1.4 DC DN . Contemporary, and the second is the wide-angle lens 16mm F1.4 DC DN . Contemporary. The third addition is this smallest mid-tele lens in its class, 56mm F1.4 DC DN . Contemporary. High-precision, rugged brass bayonet mount The brass mount combines high precision with rugged construction. | Sigma | | 56mm F1.4 Contemporary DC DN Lens for Fuji X Mount | Black | Best Buy