Sigma AF 180mm APO EX f3.5 1:1 Macro

Press Release from Sigma:

Sigma Corporation is pleased to introduce a new member of our EX series of lenses, the 180mm f3.5 EX APO Macro. This new high performance telemacro lens can focus from infinity to full 1:1 Life-size reproduction without accessories. At 1:1 reproduction the distance from subject to film plane is 18.1 inches, making this lens convenient for photographing subjects which are not easily approached, such as small animals or insects, etc. The apochromatic design and two SLD (Special Low Dispersion) glass elements, plus floating inner focus system effectively control Chromatic and Spherical Aberrations as well as Astigmatism, providing superb performance throughout the focusing range. The models for Sigma, Canon and Nikon AF cameras employ Sigma's HSM (Hyper Sonic Motor) for quiet, responsive AF function plus "full time" manual focus. A Focus Limiter switch aids in faster AF for closer or more distant subject situations, by restricting the movement of the focusing mechanism. The HSM model lenses can be used with Sigma's 1.4X EX teleconverter as a 252mm f/4.9 lens, with Sigma, Canon and Nikon AF cameras, providing AF function from infinity to about 47 inches. At closer distances, the lens automatically switches to manual focus.