It´s true that the 5D Mark III is only better in speed and AF.
But I don´t like the image quality from the D800E. In my opinion it´s not advisable to put more than 30 megapixels on a FF chip.
If you compare the image quality from the D800E with the image quality of a medium format camera the D800E loose, because the image is totally unsharp. But it´s all a question what are you willing to pay for the best image quality.
in what way are the d800 files lacking?
in all my tests the d800 absolutely leaves my 5dmk3 files for dead. far better dynamic range, especially in the darks. when the darks are lifted, the file just lightens, doesn't have any of the ugly clumping canon grain.
I have only tested up to 1000 iso (the most i ever need) , and the d800 looks better then as well- more film like in the grain. The 5dmk3 has a terrible low light quality- especially when the light has a colour cast.
the resolution is a lot more, upsizes better.
if you test the cameras- you will see that more than 30mp does hold up with sensor. the files are sharper, the graduations are smoother. have you actually shots both cameras side by side?
i also have a 60mp phase back on a contax, and although this is sharper than the nikon, i think i prefer the d800 files for the look over the phase (that has the same horrible low dark grain as the canon).
also, the tethering into a macbookpro retina with usb3 is a lot faster than the 5dmk3/usb2 - even though the files are almost twice the size.
I have tested a rented d800 for 2 days now side by side with my mk3, and file wise i can honestly sat the nikon eats the canon.
i dont really like the handling or the lenses of the nikon, so im holding out for canon to come up with an answer to the d800.
This is a placeholder, in an attempt to figure out this hateful "Access Denied - Security Block" issue!! DIE, DIE, SECURITY BLOCK!
Test, test, test.
I won't deny that the D800 is quite a phenomenal camera, and a game changer on some levels, however the benefits you talk about only really apply at ISO 100 and ISO 200, with diminishing returns at ISO 400 and above. By ISO 1600, the 5D III takes the lead, and actually has better DR at all higher ISO settings. The read noise only affects the 5D III at ISO 100 and 200, as by ISO 400 read noise on Canon sensors is the same as on Sony sensors... less than 4 electrons per pixel. Additionally, once you start pushing ISO, color noise really picks up quick on the D800, exhibiting in ALL color channels, which can be quite distracting. There have been numerous examples that demonstrate downscaling to normalize results doesn't do much to eliminate the lower noise advantage the 5D III has over the D800 either.
There are strengths and weaknesses of both cameras. If you need the best low-ISO beast you can get your hands on and don't need superb AF or a high frame rate, which generally boils down to studio and landscape photography, the D800 wins hands down... you can't beat another two stop of DR, and you can't beat the form factor for the resolution offered. But if you need versatility
, the 5D III stomps all over the D800
, despite its lackluster low-ISO performance. And that is nothing to say of Canon glass (which has improved tremendously over the last few years, in my opinion surpassing Zeiss as some of the best glass on planet Earth), nor the superior AF capabilities of Canon cameras, especially 61pt AF bodies, when paired with NEW glass (check LensRental's recent blog series on AF performance, and note the improvements in consistency and accuracy of AF when new lenses are paired with new cameras... the 1D X, 5D III, and 7D... its as accurate as the best manual focusing using maximum zoom on live view, which is about as accurate as it gets).
We could also go into the atrocious Nikon customer support that has plagued those early D800 adopters unlucky enough to get stuck with one of the nasty green-LCD bodies from earlier in the release of the D800, a problem which Nikon was and still is very reluctant to admit, let alone actually do anything about. The same green tint exists in output files to some degree, despite firmware updates, and apparently can't be fixed in post, even with hours of attempts. Thousands of customers have been screwed over by Nikon customer support, costing them hundreds of dollars for multiple return and repair attempts, along side having to jump through half a dozen hoops just to get Nikon support to even consider a repair request in the first place. Having had to use Canon service several times, I can vouch for the fact that it is worlds better than anything Nikon has ever offered... no questions asked, rapid turnaround and superb quality service every single time (although their techs are about as nerdy as they get, which often results in some rather... strange, if otherwise acceptable... phone conversations).
Its not just about how well a camera performs at ISO 100... there are dozens of other factors to take into account. I would, in all honesty, LOVE to have 14 full stops of DR... but I won't
give up anything
to get it. I like the versatility of Canon DSLR's, I LOVE Canon glass, and I couldn't live without their unwavering commitment to customer support. Canon knows they are at a disadvantage technologically right now... and they know the D800 is making waves... it may take longer than their customers wish, but I have no doubt that Canon will retaliate with something just as good, if not better, within the next year or two. They have quite a few intriguing patents up their sleeves, including a Foveon-style layered (non-bayer array) sensor (something that could make quite a few waves itself... )