What's the difference between optical and digital zoom?

有什么区别光学和数码变焦？

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Pixels, memory, optical and digital zoom, camera size and cost are all factors to compare.

像素、存储、光学及数码变焦相机体积和成本等因素比较。

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The purple emission is multi-million degree gas detected in X-rays by NASA's Chandra X-ray Observatory and the other colors show galaxies in an optical image from the Sloan Digital Sky Survey.

其中紫色喷发状物质是几百万度高温的气体，由Chandra X射线天文中心探测；其他颜色展示了斯隆数字星空调查的光学图片中的一些星系。

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Both the SL820 and SL620 are paired with Optical and Digital Image Stabilization to help reduce blur caused by hand movements.

ENGADGET: Samsung expands SL camera lineup: SL820, SL620, SL202 and SL30

Shooters have the option of simply using Optical Image Stabilization, ideal for well lit environments, or choosing Dual Image Stabilization and combining the strengths of Optical and Digital Image Stabilization.

ENGADGET: Samsung expands SL camera lineup: SL820, SL620, SL202 and SL30

Dual Image Stabilization combines both Samsung's improved Optical Image Stabilization and Digital Image Stabilization which work simultaneously to provide blur-free images no matter how shaky the user's hand may be.

ENGADGET: Samsung gets official with 14.7MP TL34HD point-and-shoot