Here it is - the DSLR every Sigma enthusiast has been waiting for since the first announcements. Externally a very similar camera to the SD14, the SD15 represents a major overhaul of Sigma's digital SLR system and even at first glance, can be seen to be a substantial upgrade in many ways. This review is a quick introduction to the hardware and some of the more obvious new features of the system, and should answer many of the questions Sigma users have been asking whilst addressing some of the requests from the SD14.