Sigma 4.5mm f/2.8 EX DC HSM LensPosted by Digital Photography Live Date November 17, 2012 Product Summary Model name: Sigma 4.5mm f/2.8 EX DC HSM Focus Type: Autofocus / Manual Format : APS-C / Crop Sensor Purchase options: Amazon | Adorama | B&H Overview This is Sigma’s premium quality...