I'm actually a little disappointed from these noise tests with raw files. It beats the D800, 7D, and 5D mark II but not by much. Looks like the Mark 3 is the best by about .5 stop (and only at high ISO), then the mark II, then the D800, then the 7D which is about a stop below the mark 3. The biggest differences seem to be a usable 12,800 iso vs the other cameras that are not...but on the raw files, the difference isn't huge. This is no Nikon D3S but then again it is 22MP which is still very large.
Are we looking at the same images? Looking at their 100% crop of the coins... 5D3 at 25K looks about the same as the 7D at 3200. And, the 5D3 at 12.8K looks much better than the 7D at 3200.
In general, I've noticed that looking at 100% crops of the 5D3 reveals obvious noise at high ISOs, but it's of a much more palatable variety and maintains much better contrast and sharpness than any other camera, especially my 7D.
I see myself using ISO 12,800 regularly and 25K in a pinch on the 5D3 where I am not happy with the noise at 3200 on my 7D and try to stick to max of 1600 ISO there. That's an effective 3 stop improvement for me.
I agree. I think that there is some confusion about sharpness vs. noise. Sharpness is merely a matter of lenses, focus, and image software processing. The AA filter is not going to play that big of a role in the D800 vs. 5D3 except when it is completely removed. All these images could be made to appear much sharper if someone simply used Lightroom to sharpen for screen display. When strictly talking about noise, someone needs to look at the shadow and the blacks, and at colors for chroma noise (odd splotches of color in areas of a single color, ideally looking at multiple patches of different colors in the image). Sensors always have more green in a Bayer array, so it is better to look at red or blue to see chroma noise. Noise always tends to go down in brighter parts of an image (even at high ISO everything is blown out white with a bright enough exposure, so the noise goes away).
This is a center crop of an image at ISO 4,000 from a Nikon D7000 (night softball game). It is simply to demonstrate that ISO 4,000 of the D7000 is the same as ISO 1,600 of the Canon 7D (basketball game photo). Both of the images are mine--I have obscured the watermark only to keep my privacy.
I have looked at all the samples and as near as I can tell the 5D3 does have at least 2 stops lower noise than the 5D2, and at ISO 12,800 should perform about the same as the Nikon D7000 at ISO 4,000.
For any Canon 7D shooters out there, I would recommend the 5D3 has a must-have upgrade. Anyone wondering whether to buy the 7D or the 5D3 should absolutely go with the 5D3 if you can afford it.
The Canon 7D was simply unbelievable in almost every aspect, and it has filled in just as good as a full-frame camera in many situations for me. It is pretty amazing that another camera came out that was 1 1/3 stops better (Nikon D7000), and it is like a miracle that another camera exists which is 3 full stops better than the 7D (3 stops is eight times better, for those who don't know the vernacular). Don't hesitate to purchase the Canon 5D Mark III!