Sigma dished out a total of three HSM OS zoom lens last year at PMA, covering as wide as 18mm to 500mm of focus distance for a variety of shoot subjects. The 09 PMA is still one and a half month away; the manufacturer is already prepping another piece of ultra zoom lens with similar features- a digital APS-C crop sensor version of 18-250mm F3.5-6.3 DC with optical stabilizer (OS) and HSM (Hyper Sonic Motor), extending 50mm more on the tele end to its popular line of 18-200mm.
The new sigma features lens construction of 18 elements in 14 groups, including four SLD glass elements and three aspherical elements to minimize ill distortions. The design is much superior comparing to the 18-200 with 15 elements in 13 groups, a pair of SLD and aspherical elements each, and theoretically better than similar offering from Tamron 18-250mm f/3.5-6.3 Di II LD Aspherical (IF) Macro.
The Sigma 18-250mm F3.5-6.3 DC OS HSM has a suggested retail of 85,700 yen ($1,080);the manufacturer will first launch a canon mounted version at February 21 2009, with announcement to follow soon in March for Sigma, Nikon, Pentax and Sony mounts.