The Canon GXX series has long been considered the natural back-up camera for DSLR users, especially those already familiar with the Canon brand.As such, the outward design of this range has changed little from its first incarnation. The Canon PowerShot G16 is no different, looking outwardly almost identical to the year-old Canon PowerShot G15 it replaces. But of course, inside there have been a few notable changes.First up is the sensor. While it remains the same pixel count, at 12.1MP, and physical size, at 1/1.7-inch, Canon says that the CMOS sensor is a completely new design, featuring back illumination.