Built-in SDM (Supersonic Direct-drive Motor). This lens features a dependable weather-resistant construction with special seals to effectively prevent water reaching the inside of the lens. It not only covers the most common focal-length range, but also provides ultra-wide-angle coverage to produce distinctive visual results, such as exaggerated perspectives or extra-wide depths of field; this makes it very useful with subjects such as sweeping landscapes and shallow indoor scenes.
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