You can call it an apples vs crabapples comparison but this is just one more of many I've done and it still has some validity.
I had a look tonite on DPR's 5D3 page..www.dpreview.com/previews/canoneos5dmarkiii/10
.. and compared raw files from 5D3, 5D2, D800 and A900 at 100 ISO to 12800.
Examine closely, with a good monitor, and you'll see the same thing I've expected to see without having to do a lot of extra testing work of my own.
Position the viewer over some of the black areas that also have dark areas right next to them. Some of the bottle reflections work well.
E.G. the Left edge of the Baileys bottle, just above the label.
Pick a point where you can see the blackness of the bottle, just above the gold band over the B.
All 4 cameras are displaying a solid black, likely because black level clipping is set to about 1 or 2 in ACR.
BUT the dark areas of reflection, just to the Right of the black area, and just above the gold band above the B, tell another story.
In this deep shadow area, both the 5D3 and the 5D2 appear to contain a bit of red channel noise, apparently even more so on the 5D3 but let's wait for a final on the raw converter to make a more accurate comparison.
The D800 and the A900 have less chroma noise in this same area and certainly appear less red-tinged to me than the 5D siblings.
Similarly red-tinged dark areas can be seen on the dark part of the white-on-black aiming cross in the middle of the scene
Caveat, the white balance on the 5D3's sample image seems a little warmer so there is a bit more red expected to show from that.
The D800 is providing slightly cleaner black and dark levels all the way up the ISO range, altho I'd rarely use more than 1600 for my work.
However, this also meets my expectations of Canon sensors showing up a fair bit of red channel noise ever since the 50D came out.
So, I'm not hopeful that I'll be pleasantly surprised when I see more rigorous testing of the 5D3. This latest Canon goodie is not going to do what I
want it to any better than their other recent products. Let's see if the 1Dx will be any better. .. or a hopefully cleaned up and improved low-iso performing sensor in a high MP FF body still to come. (soon please)
BTW, the other thing that was easy to notice was the quality of the glass used. The Canon shots delivered good detail across the frame. The D800 was really good in the central area, then not so great in the borders; win some, lose some.
Argh!! Canon, can we please have the option of custom ordering a 5D3 with a Sony sensor? Even a 22MP one?
That'd be king. And worth $5k for sure.