LAS VEGAS -- These days, I always look forward to a lens announcement from Sigma, and at least one of its CES debuts has "want" scribbled in my mental tracking list. That's a reworked version of its 50mm f1.4, the Sigma 50mm F1.4 DG HSM Art. The other update, the 18-200mm F3.5-6.3 DC Macro OS HSM Contemporary, doesn't float my boat as much but sounds like it might be a reasonable kit lens alternative, depending upon the price (the current model is $499).
The full-frame 50mm f1.4 replaces an almost 6-year-old model that's still available, but not even listed on Sigma's site. It's got tweaked optics -- lower-dispersion lenses, repositioned elements for decreased movement during focus, and better focusing algorithms. Plus, it can now focus a little closer, 15.7 inches vs. about 18 for its predecessor. It's also been physically redesigned to match the rest of the company's higher-end lenses.
The APS-C 18-200mm F3.5-6.3 DC Macro OS HSM replaces the 2-year-old model, and like the 50mm it gains a couple of inches closer focusing, down to 15.4 inches. It also incorporates more modern low-dispersion lenses, and Sigma claims better aberration correction at the long end. It's also smaller than its predecessor, though not by a significant amount.
Sigma has not yet revealed pricing or availability for either lens, nor has it mentioned specific mounts.