聚焦系统
| 最大焦距（35mm胶片当量） |
300 mm |
| 最小焦距（35mm胶片当量） |
120 mm |
| 光阑叶片数量 |
9 |
| 最大光圈 |
22 |
| 光圈范围 |
2.8 - 22 |
| 复制比率 |
1:8.1 |
| 组件应用 |
SLR |
| 焦距调整 |
Auto/Manual |
| 图像稳定器 |
Y |
Telephoto Zoom Lens, APO 120-230 mm, F2.8 EX DG OS HSM, Diameter 105mm, 2.950 g
A digitally optimised telephoto zoom lens covering ultra-telephoto up to 300mm, incorporating Sigma's Optical Stabilisation system and a fast maximum aperture of F2.8 at all focal lengths.
This large aperture telephoto zoom lens incorporates Sigma’s proprietary Optical Stabiliser system and offers ultra-high resolution, comparable to a fixed focal length lens. One SLD and two FLD glass elements are used for maximum correction of chromatic aberrations. This lens adopts an inner focusing and inner zooming system to ensure sharp images throughout the entire zoom range. The OS system offers the use of shutter speeds approximately 4 stops slower than would otherwise be possible, enabling hand held tele-photography. Sigma’s APO Teleconverters can be used with this lens.
<b>Ultra-high resolution</b>
One SLD (Special Low Dispersion) and two FLD (“F” Low Dispersion) glass elements are used for maximum correction of chromatic aberrations. Improved optical performance provides excellent correction of sagittal coma flare and ensures ultra-high resolution, comparable to a fixed focal length lens.
<b>Super Multi-Layer Coating</b>
Sigma’s Super Multi-Layer Coating reduces flare and ghosting and provides sharp and high contrast images throughout the entire zoom range.
<b>Sigma’s proprietary OS system</b>
Sigma’s proprietary OS (Optical Stabiliser) system offers the use of shutter speeds approximately 4 stops slower than would otherwise be possible, enabling hand held tele-photography. The Optical Stabiliser in this lens has two modes, Mode 1 is ideal for general photography and Mode 2 is designed for panning subjects such as racing cars.
<b>Inner focusing and zooming system</b>
The lens design incorporates an inner focusing and inner zooming system. The overall length of the lens does not change during focusing and zooming, ensuring convenient handling. The inner focusing system also eliminates front lens rotation, making the lens particularly suitable for using circular polarising filters. A removable tripod collar (TS-31) is included as a standard component.
<b>Quiet and high speed autofocus</b>
Incorporation of HSM (Hyper Sonic Motor) ensures quiet and high speed autofocus, while allowing full-time manual focus override.
<b>Rounded diaphragm</b>
This lens has a rounded 9 blade diaphragm which creates an attractive blur to the out of focus areas of the image.
<b>APO Teleconverter</b>
The addition of Sigma’s 1.4x EX DG APO or 2x EX DG APO Teleconverters produce a 168-420mm F4 AF telephoto zoom lens or a 240-600mm F5.6 AF telephoto zoom lens respectively.
