It's interesting to see the different approaches taken by each manufacturer to keeping visible noise as low as possible at such high sensitivities. Sony are applying a combination of NR with the emphasis on luminance reduction (hence the slightly soft pastel-like images at ISO 3200), Nikon have gone (as they always do) for primarily chroma noise reduction which produces more detailed images with a more natural film-like grain. The other two appear to have struck a balance between these two. Overall the Nikon D300, Canon EOS 40D and Olympus E-3 all produce equally as good images (if with different 'looks'), the A700 images look a bit over processed.
