MIDTONE banding with gray fog and blue skies are where i first noticed problems with Canon images when I had my 5d2, ages ago.
Shadow pushing landscapes with every Digic 4 body showed me the FPN issues in shadows.
Quick testing of my 5d2 showed me that FPN was readily visible in smooth shades only 2 or 3 EV below metered middle if pushed only +1 stop.
I still maintain it was the most disappointing body I ever had, and possibly a lemon but... there were more of them out there like that.
I'm feeling somewhat vindicated by so many more of you, some who've previously argued against these very observations, corroborating this problem.
My only question is, WTH took so long for some users of same equipment to notice this?!?
Well, I'd noticed the banding with the 7D a long time ago. I also acknowledged it a long time ago, in many posts. The 7D banding is easier to clean up, since it is so extremely regular (they span eight pixels, the stride of the ADC channels). The 5D III banding is different. It's not as pronounced, per-se, but it is still there...and it does NOT clean up well with Topaz DeNoise 5. I only got the 5D III maybe four or five months ago? So, it's been only relatively recently that I got enough personal, first-hand time with the 5D III to fully realize how frustrating its banding issues are. That may account for why it "took me so long", as you put it. ;P
I am happy with the 5D III at higher ISO, however it has been rather disappointing for me at lower ISOs. I thought it would be better...and it simply isn't. ISO 400 with BIF against a blue sky can sometimes be really ugly at times. I don't feel that it has much in the way of shadow pushing at all. If your very careful, use heavy GND to compress contrast on-scene, ETTR like mad (which is also another weak spot of the 5D III...it burns highlights), then you might not actually have to lift a stop. The shadow falloff still isn;t good, though....you can see the poor quality of the shadows even without pushing. The only real remedy there is to crush the blacks a bit...but I've never been a big fan of stark contrast in landscapes...
So yeah. I really do notice the issue now...it's depressing.
Well, I'm sure many have noticed it, and just worked around it.
I myself noticed it years and years back, actually when the 5D Mark II was first released. But I usually got eaten alive when I mentioned it (not just here, in fact). Even by people like jrista some 2+ years ago, sadly! Ironically, jrista, one of your counter-arguments back then was something about more highlight headroom with Canon files. Which just isn't the case - most of these sensors map the data off the sensor in a linear fashion, so there should be no difference between brands, cameras, etc. Save for maybe the D810 at ISO 64, where DxO full SNR curves suggest non-linearity - which'd essentially mean that highlights that 'look' clipped in fact aren't b/c they've been rolled off. Honestly, I'm suspicious about that... actual non-linearity at the sensor level is kind of a holy grail, so I'd expect Sony or Nikon or DxO or someone
to be ranting mad about that if they'd actually achieved it.
But anyway your comment years ago about highlight headroom and my D800/5D3 comparison being bull is particularly ironic now in light of you mentioning the highlights burn easily
Which, btw, I'm not so sure is entirely, quantitatively, accurate... again, since these systems map the data linearly. Unless there's some difference in (non-)linearity of charge build-up in the photodiodes, but unless you've really done some thorough side-by-sides, I wouldn't go around claiming one system has more highlight headroom than another.