The Sigma 105mm f/2.8 EX DG OS HSM Macro Lens is a large aperture medium telephoto macro lens that offers advanced performance of close-up photography. Sigma's own proprietary OS (Optical Stabilizer) system enables handheld close-up photography. A Special Low Dispersion (SLD) lens and one high refractive index SLD lens provide excellent correction for all types of aberration and distortion. A floating focusing system moves two different lens groups in the optical path to different positions. This system compensates for astigmatic aberration and spherical aberration and provides extremely high optical performance from infinity to 1:1 Macro.
The Super Multi-Layer Coating reduces flare and ghosting, providing high contrast images. It is also possible to use this lens with Sigma's APO TELE CONVERTERS. The HSM (Hyper Sonic Motor) ensures quiet and high speed autofocus as well as full-time manual focus capability. This lens features a rounded 9 blade diaphragm creating an attractive blur to the out of focus areas of the image.
Large aperture medium telephoto macro lens - This medium telephoto macro lens allows you to maintain an appropriate distance from subjects while still getting close up photos. Since the working distance at its closest focusing position is 142mm, shadows of the lens and camera will not affect photography making it suitable for taking photos of subjects, such as flowers, under natural lighting conditions. In comparison to the Sigma 50mm and 70mm macro lenses, the main subjects can be defined with perfectly smooth and blurred backgrounds.
High rendering performance - The lens power layout produces excellent optical performance. High refractive index SLD (Special Low Dispersion) glass corrects chromatic aberration, spherical aberration and field curvature. It ensures high rendering performance at all shooting distances. The Super Multi-Layer Coating reduces flare and ghosting, maintaining quality images with high contrast.
Handheld photography with ease - Sigma's OS (Optical Stabilizer) system offers effective correction of approximately 4 stops. As the stabilization effect is visible through the viewfinder, it aids composition and accurate focusing.
Floating inner focusing - This lens incorporates floating inner focusing which moves two lens groups separately. This minimizes aberrations which occur as shooting distance changes, and enables stable rendering of the image from infinity to 1:1 magnification. This also corrects image distortion, especially when taking close-up pictures. Since focusing does not change its overall length, this lens is easy to hold and use.
Quiet and speedy AF - HSM (Hyper Sonic Motor) provides quiet and high speed AF. It is also possible to use full-time manual focus, even if the lens is set to autofocus.
Rounded 9 blades diaphragm - This lens has a rounded 9 blade diaphragm which creates an attractive blur to the out of focus areas. This also creates smooth, rounded out of focus highlights when taking photos which have a strong light source in the background such as lights shining on the surface of water.
APO Tele converters - This lens is compatible with Sigma's APO TELE CONVERTERS. With APO TELE CONVERTER 1.4x EX DG, it can be used as 147mm F4 AF telephoto macro lens, and APO TELE CONVERTER 2x EX DG as 210mm F5.6 MF telephoto macro lens. This allows a greater working distance while still achieving 1:1 macro magnification.