What makes the 5D Mark IV better in terms of autofocus capabilities is that this camera has 61 focus points while the 6D Mark II has only 45 focus points. On the other hand, only 41 AF points in the 5D Mark IV are capable of being cross-type, while all of them can become cross type in the 6D Mark II. Tough question here. The 5D series is definitely a better choice for video and faster shooting opportunities. And the Mark IV is better than the Mark III for those specific reasons. But in terms of image quality all will be very good. The Mark III and 6D are comparable in terms of IQ, but the Mark IV is ahead of both of them. The 6D's 35.8 x 23.9mm CMOS image sensor might be a bit smaller than the imaging chip in the Canon 5D Mark III, but its individual photosites are bigger since it has slightly less resolution. I wouldn't bother with the 5D II and its fixed pattern banding, the 5D III is good but doesn't have the 5D's look, and the 6D has the best image quality by far of those three but it's not the same look as the 5D, only the Mark II N has that look I know you want. Canon 5D Mark III vs. Fuji X100S image quality 09 January 2014. Canon 5D Mk III vs. LEICA M 240 vs. Sony A7 Image Quality Comparison 19 December 2013. Canon 6D. Similar image quality smaller, lighter package with a few less controls, but with added Wi-Fi and GPS. Canon 5D Mark III versus Canon 6D. Canon EOS 6D Mark II vs EOS 5D Mark IV: Performance. Canon EOS 6D Mk2: 45 point AF system (all cross-type) Canon EOS 5D Mk4: 61 point AF system (41 cross-type) Yet, they knew that image quality is the #1 selling point, so they couldn't market it with, "Same image quality with better AF and lots of tweaks." Instead of making improvements to the sensor hardware, they increased the noise reduction in JPEG processing and allowed two stops higher ISO--equivalent to pushing a 5D2's "H2". Finally, the Canon EOS 6D Mark II sports a vari-angle touchscreen LCD, which is great for photographing pets. You’re able to adjust the screen and easily capture lower angles without hurting your back in the process! 2. Canon EOS 5D Mark IV. Image from Amazon. Canon EOS 5D Mark IV. htmkXQ.