Ok, I just bought a Sigma 18-50mm F2.8 EX DC and here I am posting about the Sigma 17-50mm F2.8 EX DC OS. Sounds the same? Well, no! Sometime in May 2010, Sigma launched the upgraded model to include Optical Stabilizer (OS) or in Nikon speak, VR, or Canon speak, IS, or Tamron speak, VC and whatever else the others call it.
It has a different lens construction compared to the 18-50mm F2.8 to possibly cater for the slightly wider angle (17mm instead of 18mm), a larger filter size diameter of 77mm, about 25% heavier at 565g, not a “MACRO” lens with minimum focusing distance of 28cm instead of 20cm and of course with Optical Stabilizer which allows for up to 4 stops slower. It is currently available for Sony, Nikon, Canon, Pentax and of course Sigma mount! Recommended retail price is approximately USD900-1,000.
More information from Sigma’s website.