Al PMA Sigma ha lanciato diversi obiettivi. Uno di essi è l'APO 70-200mm F2.8 EX DG OS HSM, un teleobiettivo a grande apertura con sistema di messa a fuoco ad ultrasuoni. Il nuovo zoom si avvale di un “vetro FLD” per ridurre le aberrazioni.
Press release ufficiale (lingua inglese)
February 21, 2010: The Sigma Corporation is pleased to announce the new Sigma APO 70-200 F2.8 EX DG OS HSM.This large aperture telephoto zoom lens incorporates Sigma’s original Optical Stabilizer function.
The lens covers a medium telephoto range of focal lengths from 70mm to 200mm and has a large maximum aperture of F2.8 throughout the entire zoom range. The OS (Optical Stabilizer) function offers the use of shutter speeds approximately 4 stops slower than would otherwise be possible.* For Sony and Pentax mount, the built-in OS function of this lens can be used even if the camera body is equipped with an image sensor shift anti-shake system.
As compensation for camera shake is visible in the view finder, the photographer can easily check for accurate focus and ensure there is no subject movement.* Two FLD (“F” Low Dispersion) glass elements, which have the performance equal to fluorite glass, and three SLD (Special Low Dispersion) glass elements provide excellent correction of color aberration.
High image quality is assured throughout the entire zoom range and an optimum optical power layout provides superior optical quality in all shooting ranges from close-up to infinity. Super Multi-Layer Coating reduces flare and ghost.* This lens incorporates HSM (Hyper Sonic Motor), ensuring a quiet and high speed AF as well as full-time manual focus capability.
The lens has a minimum focusing distance of 140cm (55.1”) throughout the entire zoom range and a maximum magnification ratio of 1:8.* The rounded 9 blade diaphragm creates an attractive blur to the out of focus images.* This lens is equipped with a Petal-type hood.* For digital cameras with an APS-C size image sensor, a dedicated hood adapter, which expands the length of the lens hood, is supplied