不搞笑，这事儿得怪sony

D300s那块CMOS (K-x用的那块12MP的属于同一个系列)的ISO100是扩展出来的，扩展的意思是本来没有，充点硅胶啥的给您将就用，效果就不太保证了

[arnold 编辑于 2010-08-19 19:30]

耐克好搞笑。。。ISO3200时居然比100时强。。。

ISO400也很优秀

至少证明Ｋ７在ISO 100 和200是非常优秀的。

最后再看尼康D300S在不同感光度下的在动态范围：

http://www.dpreview.com/reviews/nikond300s/page17.asp

ISO Sensitivity and Dynamic Range
The base sensitivity of the sensor used in the D300S is ISO200. There is also a Lo 1.0 mode that attempts to mimic ISO 100 but it's effectively just ISO 200 over-exposed by a stop. The result is that the sensor becomes saturated and clips to white quite easily, limiting that mode's dynamic range. For most applications, you'd be better off buying a neutral density filter if you need slower shutter speeds than ISO 200 will allow.

Beyond ISO 200 the highlight dynamic range remains a fairly stable 3.8 stops above middle gray. The shadow range appears to increase but this is most likely to be a result of noise reduction dropping noise to below our cut-off threshold. Even so, around 8.5 EV of dynamic range with nearly 4 stops above middle gray is an impressive result.

Sensitivity    Shadow range  Highlight range  Usable range  
ISO 100 equiv.   -5.0 EV        3.1 EV           8.1 EV
ISO 200          -4.6 EV        3.8 EV           8.4 EV
ISO 400          -4.8 EV        3.8 EV           8.6 EV
ISO 800          -4.8 EV        3.8 EV           8.6 EV
ISO 1600         -4.8 EV        3.8 EV           8.6 EV
ISO 3200         -4.7 EV        3.8 EV           8.5 EV
ISO 6400         -3.7 EV        3.7 EV           7.4 EV

再看佳能7D在不同感光度下的在动态范围：

http://www.dpreview.com/reviews/canoneos7d/page17.asp

ISO Sensitivity and Dynamic Range
Although noise cuts the shadow range at the very highest ISO settings the EOS 7D's JPEG dynamic range is pretty consistent up to ISO 3200. The range - around 8.3 EV - is fairly typical for a camera at this level.
Sensitivity Shadow range  Highlight range  Usable range  
ISO 100        -5.0 EV        3.3 EV__________8.3 EV
ISO 200        -4.9 EV        3.4 EV          8.3 EV
ISO 400        -5.1 EV        3.3 EV          8.2 EV
ISO 800        -4.9 EV        3.4 EV          8.3 EV
ISO 1600       -4.8 EV        3.4 EV          8.2 EV
ISO 3200       -4.3 EV        3.5 EV          7.8 EV
ISO 6400       -3.4 EV        3.5 EV          6.9 EV
ISO 12800      -3.0 EV        3.5 EV          6.5 EV

先看K-7在不同感光度下的在动态范围：

http://www.dpreview.com/reviews/pentaxk7/page18.asp

ISO Sensitivity and Dynamic Range
While the K-7's highlight range remains relatively constant the measured shadow range decreases as you go up the sensitivity scale. This is mainly due to increased noise and noise reduction smearing.

Sensitivity Shadow range  Highlight range  Usable range  
ISO 100       -5.7 EV          2.9 EV        8.6 EV
ISO 200       -5.5 EV          2.9 EV        8.4 EV
ISO 400       -5.5 EV          2.9 EV        8.4 EV
ISO 800       -4.3 EV          2.9 EV        7.2 EV
ISO 1600      -3.4 EV          2.8 EV        6.2 EV
ISO 3200      -2.1 EV          2.7 EV        4.8 EV
ISO 6400      -1.3 EV          2.4 EV        3.7 EV

以ISO800为华丽的分界线，K-7的动态范围无可挽救的直线下降…

[arnold 编辑于 2010-08-19 19:05]