I know that 5Dmk3 reviews have been done to death, so I’ll try to skip over the really obvious stuff.
I have mixed feelings about the Mark 3. I used one on a music video the other day, and I do really like the design. It’s solidly built, the aperture wheel feels nicer than ever before, the LCD screen is huge, high-res and widescreen. It’s the little things that count here, that’s what I’m saying. The camera alerts you if you’re trying to scroll the aperture wheel while it’s locked. The menus have been redesigned, and while they initially seem more complex (there are fewer menu sections, but each section has 4 pages) I think it’s well thought out. Previously, functions such as Highlight Tone Priority needed to be added to the “favourites” menu to be accessed quickly. Now HTP and ALO reside in the same menu section as your picture style settings, which is a lot more logical. It’s also easy to find quite obscure cutomisation functions, such as assigning the shutter button to record video rather than take a still shot. That kind of thing.
Again, I’m not going to talk about image quality in detail here. All I’ll say is I think it’s a real pity about the codec “fizz” that is apparent even at low ISO settings. I really like the fact that you can record all I-frames, that’s a big thing for me. And despite the “fizz”, I’d much rather shoot with the Mark 3’s highest quality video codec than with the old codec on the 5D2 and 7D. The fizz seems most obvious in the mid-shadow tones, and if you’re looking for it, it’s easy to find. Still, I prefer it to the old long-GOP compression which might be cleaner on a static shot, but present much more damage and artefacting on shots with a lot of detail and movement. At least the Mark 3’s fizzing is consistent, like a texture or grain to the image (maybe that’s a stretch).
Is this a revolutionary camera for shooting video? Of course not. Showing other people the footage, you’d most likely have to *tell them* “I shot that on a 5D mark 3” in order for them to see any difference. At the end of the day, shooting on a Mark 3 feels much the same as DSLR shooting always has. But if you need that full-frame sensor look, this is still one of your best options (until “Red Dragon”— or whatever Mr. Jannard decides to call it — comes out). Personally, if the D800 didn’t have moire problems, I’d see it as a winner against the Mark 3. Uncompressed HDMI output (hopefully firmware updates will make it more compatible than it currently seems to be) and a potential extra bit of sharpness compared to the Mark 3 sounds pretty compelling. But you’ve got to weigh that up against better low light performance, greatly reduced moire problems, slightly shallower DOF (the D800 goes to a 1.1x crop for FX video shooting) and Canon lens compatibility on the Mark 3. So it gets a bit murky. For shooting music videos and the like, I don’t really need extreme ISO sensitivity, and moire problems are usually avoidable in most shots — and I just like recording straight to Prores. But for many purposes the Mark 3 beats the living daylights out of the D800.. so go figure.
To be honest, I’m just looking forward to see what the FS700 is like. Debating Mark 3 vs D800 is like arguing about whether to get McDonald’s or KFC for dinner, when there’s an incredible Japanese restaurant across the road. Let’s move on.