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虽然近几年来数码摄影技术突飞猛进,数码影像在质量上提高很快,但在同等价格下,用数码相机拍出的照片在色彩还原和影调层次上都还不能和传统相机相比。尽管数码相机在拍摄的机动性和后期处理等很多方面都要比传统银盐摄影有优势,但它的一个致命的竞争弱点就是动态范围。动态范围是什么?动态范围有点类似传统摄影里的曝光涵盖范围概念,也就是胶卷能在一个画面里包含的景物亮度范围。在传统摄影里,我们都知道一般的负片能涵盖10档曝光量,即最暗和最亮的地方能有大约1:1000(2的10次方)的光比;反转片能涵盖7档曝光量,也就是约1:128(2的7次方)的光比。数码相机的CCD或CMOS的涵盖范围要更差一些,虽然高档专业相机理论上能涵盖1:65536(2的16次方,即每通道16位色深)的光比,但一般的家用数码相机实际还原能力大概只能达到1:64左右,专业数码相机在用JPEG格式拍摄时动态范围也比这高不了多少。
Although the technology of digital photography has been advancing by leaps and bounds and the quality of digital video has been rapidly improved in recent years, at the same price, photos taken with digital cameras can not be compared with traditional cameras at the color reproduction and tone level. Although digital cameras offer many advantages over traditional silver photography in many aspects, such as camera mobility and post-processing, one of the fatal competitive weaknesses is the dynamic range. What is the dynamic range? The dynamic range is a bit like the concept of exposure coverage in traditional photography, which is the range of scene brightness a film can contain in one frame. In traditional photography, we all know that a typical negative can cover up to 10 exposures, the lightest and brightest of which can have a light ratio of about 1: 1000 (2 × 10 power); the reversal film can cover up to 7 gears The light exposure, that is, the light ratio of about 1: 128 (2 power of 7). Digital camera CCD or CMOS coverage to be even worse, although the high-end professional camera can theoretically cover 1: 65536 (2 of 16 power, that is, each channel 16-bit color depth) of the light ratio, but the general home digital camera The actual reduction of about only about 1:64 capacity, professional digital camera when shooting in JPEG format dynamic range is not much higher than this.