Maybe that was a bit the case in terms of video. But even there, we forget how Hollywood production companies using 5D Mark II - and even 7D - bodies to film network shows would have 8-10 of those Canon bodies on set to swap out every 5-10 minutes of shooting time when the one they were using started getting a bit hot and thus noisy. The others were in various stages of cooling back down. No one complained about the thermal limits back then because no other "stills" camera could even shoot video at near the quality of the 5D Mark II. Dedicated video cameras priced anywhere remotely near the combined price of 8-10 5D Mark II bodies didn't have sensors that large. It was over a decade later when the R5 introduced 8K recording - with less restrictive thermal limits shooting 8K than the 5D Mark II had when shooting FHD before it started getting noisy as h3!! - that the Sony fanboy marketing machine erupted in howls of protest that Canon had deceived them about the R5's 8K capability. When the 5D Mark II revolutionized the idea of hybrid stills/video cameras in 2008, the big bang which created the Sony α7 FF mirrorless universe was still half a decade in the future.
Anyone who doesn't see the quantum difference between the 5D Mark II and the 5D Mark III/IV as stills cameras never tried to shoot sports or action with the 5D Mark II before actually being able to effectively do so with the 5D Mark III and then Mark IV. They weren't the 1D X, but they were
true advancements over the 1Ds Series apart from the smaller form factor and battery, and moderately lower body durability.
There was a very real demarcation line between the 5D Mark II, with a world class sensor but also many consumer level features (like the lackluster - even in bright light - AF system that could not focus at all in slightly dim light, much less in true low light), and the 2012 5D Mark III. For all practical purposes the 5D Mark III was the replacement for the 1Ds Mark III in a non 1-series form factor.
Keep in mind that the 2007 1Ds Mark III and 2007 1D Mark III introduced only a year before the 2008 5D Mark II weren't even capable of shooting video at any resolution. Video is almost certainly why the 1D Mark IV, but not a corresponding 1Ds Mark IV, was introduced on such a short cycle in 2009. The 1D X was rolled out and the 1Ds Mark III discontinued in 2012, the same year the new 5D Mark III debuted.
Using the 5D Mark III prompted
Uncle Roger to say:
"It’s a bit amazing to think that the 5D Mk II was almost 4 years old when the Mk III hit the shelves. I’ll admit that I was expecting the Mk III to be very different than this. I’ll even admit I had some panic when I realized Canon was doing what I’d said for years it was time to do: stop increasing megapixels and work on other things. I thought I wanted that, but then the other guy had this 36MP camera…"
"What will you notice right away? Autofocus. Leave it on factory settings until you have a bit of time with the menu (because there are pages of autofocus menu options) and it’s better than any Canon camera I’ve ever shot with. Bad light? No problem. Moving subjects? No problem. It hit autofocus on my jet black dog Zeiss (yeah, that’s really his name) running around the back yard in near darkness."
"You want more? High ISO performance is spectacular. ISO 6400 is about as good as 3200 was on the 5D II. The LCD is significantly better; you’ll notice it at a glance. I love the “self-teaching” menu: hit a button and an explanation of the menu item your looking at pops up. It’s like having the manual built into the camera. It’s far more customizable than the 5D II was, and it’s easier to customize for what you want at a glance."
"The sensor is now heat-sinked, which means no more 6-minute video limit. And I have to mention dual memory card slots, AF select points that automatically change when you go from landscape to portrait mode, side-by-side image comparison, in-camera HDR, JPEG processing that automatically corrects chromatic aberration (Canon brand lenses only), and a much quieter shutter with silent-shutter option."
"This is no minor upgrade camera; it’s an entirely new camera using the old camera’s name. And it’s better—in every way. After just a few hours with it (30 minutes of which was a lesson from Tim about using the autofocus system) this camera has grown on me like salmonella on room temperature chicken. I absolutely love it and have set aside my 5D II for good. -
January, 2013"
A few months later in his epic blog post
Autofocus Reality Part 3B he remarked:
"Despite my well-recognized modesty, I will also point out that when the 5D Mk III was first released, and Canon fanboys were dropping off cliffs right and left, I
said 'the 5D III is no minor-upgrade camera; it’s an entirely new camera using the old camera’s name'. Its autofocus system is certainly not a minor upgrade–it’s moved over to the big-boy camera side."
