“Finally let's take a look a the K-7's RAW output next to the competition. Removing any in-camera noise reduction and processing the images using Adobe Camera Raw (V5.4 in this case, all NR set to 0) gives us the nearest thing to a 'level playing field' for assessing the relative noise levels of the four cameras' sensors.
With noise reduction turned off we get a more accurate idea of how noisy these sensors are and the image looks slightly different to what we've seen above in the JPEG section of this page. In the RAW comparison the K-7 and K20D can easily keep up with the competition from Nikon and Canon. Surprisingly the older model K20D even outperforms its successor at higher sensitivities and produces slightly cleaner RAW files.”
dpreview的结论说：“The four cameras compared here produce similar amounts of noise at all ISO settings. The EOS 50D measures the largest amount of chroma noise and the K20D is producing the lowest RAW noise levels pretty much across the range.”
dpreview结论是这样说的：“the Nikon and Pentax perform better in numerical terms at lower ISOs, at the pixel level, but are overtaken by the 7D at the really high ISO settings, comparing on the whole-image level, you'd be hard pressed to spot any advantage.”
dpreview是这样说的：“At higher sensitivities it's obvious that Pentax is applying far less luminance noise reduction than Canon or Nikon. On the plus side this means that detail is retained and the results look visibly sharper; the downside is that noise is, inevitably, considerably more obvious. On balance, for viewing at normal magnifications (when color noise is still visible), the Canon and Nikon approach is preferable for JPEGs (though once you get to ISO 6400 none of them is that impressive).”
