聚焦系统
| 最近聚焦距离 |
0.3 m |
| 光阑叶片数量 |
7 |
| 对角线视角（最大） |
69.3 ° |
| 最大光圈 |
22 |
| 组件应用 |
SLR |
Digital Camera Lens 18-50mm f/2.8-4.5 DC OS HSM
Large aperture standard zoom lens designed exclusively for digital SLR cameras and incorporates Sigma's original OS (Optical Stabiliser) function.
This standard zoom lens is designed exclusively for digital SLR cameras and incorporates Sigma's original OS (Optical Stabiliser) function. This lens offers a large aperture of F2.8 at the 18mm focal length making it ideal for indoor photography and in low lighting conditions. Two SLD (Special Low Dispersion) glass elements and three aspherical lenses provide excellent correction for all types of aberrations. High image quality is assured throughout the entire zoom range. The incorporation of HSM (Hyper Sonic Motor) ensures a quiet and high speed AF. The Super Multi-Layer Coating reduces flare and ghosting and provides high contrast images. This lens has a minimum focusing distance of 30cm (11.8 inches) throughout the entire zoom range and a maximum magnification ratio of 1:4.1 making it ideal for close-up photography.
Superior image quality throughout the entire zoom range
Two SLD (Special Low Dispersion) glass elements and three aspherical lenses provide excellent correction for all type of aberrations. High image quality is assured throughout the entire zoon range.
A bright image through the viewfinder
This lens offers a large aperture of F2.8 at the 18mm focal length. This large aperture provides a bright image through the viewfinder and enables photographers to easily check focusing and composition. The near circular diaphragm creates an attractive blur to the out-of-focus areas which enables photographers to emphasise the subject.
Sigma’s own unique OS (Optical Stabiliser) technology
This lens is equipped with Sigma's own unique OS function. This system allows the photographer to use shutter speeds approximately 4 stops slower than would otherwise be possible whilst still eliminating camera shake. For Sony and Pentax mounts, the built-in OS function of this lens can be used even if the camera body is equipped with an anti-shake function. As compensation for camera shake is visible in the viewfinder, the photographer can easily check for accurate focus and ensure there is no subject movement.
· It is not possible to use the built-in OS function of this lens when using with Pentax ist* series and K100D DSLR cameras.
Quiet and fast AF
An internal focusing system and HSM (Hyper Sonic Motor) ensures quiet and high-speed auto focus.
· AF will not function with Pentax camera bodies that do not support HSM.
High contrast images
The Super Multi-Layer Coating reduces flare and ghosting and provides high contrast images throughout the zoom range.
Convenient handling
The lens design incorporates internal focusing and zooming systems, therefore the overall length of the lens does not change during focusing and zooming, ensuring convenient handling. The inner focusing also eliminates front lens rotation making the lens particularly suitable for use with circular polarising filters and the supplied petal-type hood.
Minimum focusing distance of 30cm throughout the entire zoon range
A minimum focusing distance of 30cm (11.8") throughout the entire zoom range and maximum magnification ratio of 1:4.1 makes this lens ideal for close-up photography
* Vignetting will occur if the lens is used with digital cameras with image sensors larger than APS-C size or 35mm SLR cameras.
