聚焦系统
| 最大光圈 |
32 |
| 焦距 |
180 - 300 mm |
| 光圈范围 |
4 - 5.6 |
| 组件应用 |
SLR |
AF70-300mm F/4-5.6, Di LD Macro 1:2
Tamron's lightweight, compact, high-image-quality telephoto zoom lens with macro capability of 1:2 has improved multi-coating for optimised performance with digital SLR cameras as well as film cameras.
Flipping a macro switch in the focal length range of 180mm to 300mm obtains a maximum magnification ratio of 1:2 at an unsurpassed minimum focus distance of 95cm, enabling close-up shots of flowers, insects, and other objects that normally require the use of a specially designed macro lens.
Designed for optimum handling ease and portability and weighing only 458g, this lens offers the distant capture and foreshortening effects characteristic of the 300mm ultra-telephoto world. It's ideal for handheld shooting with full-frame and APS-C format SLRs.
<b>Sharpens edges by reducing 'colour fringing'</b>
Chromatic aberration occurs when a lens element refracts different wavelengths of a ray of light – its rainbow colours – at very slightly different angles. This results in the 'colour fringing' that reduces the sharpness of an image. LD elements are made from special glass materials with extremely low dispersion indices (i.e. the refraction of a ray of light into rainbow colours is extremely narrow). Thus they effectively compensate for chromatic aberration at the centre of the field (on axis), a particular problem at long focal lengths (the telephoto end of the zoom range), and for lateral chromatic aberration (toward the edges of the field) that often occurs at short (wideangle) focal lengths.
Although costly, LD glass materials result in clear, vivid image quality.
