Canon EOS-1D X Mark II vs Canon EOS-1D X: 07 LCD screen and viewfinder
At 3.2-inches, the Canon EOS-1D Mark II's LCD Clear View II LCD screen is the same size as the EOS-1D X's.
However, not only is it higher resolution - 1620K dots versus 1040K dots - the EOS-1D X Mark II's rear display is a touchscreen.
The touchscreen is only activated during Live View stills or movie recording - enabling the selection of AF points and a magnified view - but it's more than the EOS-1D X has. In fact, it's the first Canon full-frame camera to offer touchscreen operation.
The EOS-1D X Mark II gets Canon's new Intelligent Viewfinder II, as introduced in the EOS 7D Mark II.
Canon EOS-1D X Mark II vs Canon EOS-1D X: 08 4K movies
It isn't the first Canon DSLR to offer 4K video recording - that honour goes to the Canon EOS-1D C - but the EOS-1D X Mark II is the first to offer 4K at 60fps. In fact, the EOS-1D X Mark II goes one better with its Full HD 1080p video, which can be recorded at 100/120fps.
Faster frame rates are sought after by filmmakers who want to exploit slow-motion playback. The original EOS-1D X didn't offer any form of high frame rate movie recording, with its Full HD movies topping out at 25/30p.
What's more, the EOS-1D X Mark II enables you to pull 8.8MP stills from 4K footage.
As we've highlighted, the EOS-1D X Mark II also boasts a touchscreen. Twinned with Canon's Dual Pixel CMOS AF, this enables pin-point shifts in focus while recording movies. The original EOS-1D X offered Contrast-detection AF for Live View, with no continuous autofocus.
Canon EOS-1D X Mark II vs Canon EOS-1D X: 09 build quality and handling
The EOS-1D X Mark II is marginally taller and deeper than its predecessor, and both weigh the same. There has been a subtle reshaping in some areas of the body though, such as the Mark II's recessed area for the M-Fn button which makes it easier to find with your eye pressed to the viewfinder.
The thumbsticks ('Multi-controllers' in Canon speak) have larger, ridged surfaces, and the Live View button has a more user-friendly Live View/Movie shooting switch and start/stop button arrangement than the outgoing model.
To cope with the accelerated shooting speed, Canon has redesigned the mirror in the EOS-1D X Mark II, with the new two-motor system drives the mirror and shutter cocking independently of each other.
Other useful 'under the hood' features that the EOS-1D X Mark II offers over the Mark I include a customisable Quick Control Screen and a Digital Lens Optimizer.
While the EOS-1D X included peripheral illumination, distortion and chromatic aberration corrections with compatible lenses attached, the EOS-1D X Mark II goes a step further and adds diffraction correction. This can be applied during or after taking a photo.
Canon EOS-1D X Mark II vs Canon EOS-1D X: 10 connectivity
Like its predecessor, the Canon EOS-1D X Mark II doesn't offer built-in Wi-Fi - for that, you'll need Canon's Wireless File Transmitter WFT-E8 or WFT-E6. The transmission speeds of the new Mark II-compatible WFT-E8 transmitter are faster.
It does come with built-in GPS though. The EOS-1D X Mark II will add Geotag data to the image metadata, and offer a logging function to track the camera's movements on mapping systems.
Both cameras can send images over a network via their built-in Ethernet sockets, but the EOS-1D X Mark II upgrades the USB to SuperSpeed USB 3.0 versus the EOS-1D X's Hi-Speed USB 2.0.
Canon EOS-1D X Mark II vs Canon EOS-1D X: 11 battery life
While not leaping ahead in terms of battery life, the Canon EOS-1D X Mark II's new LP-E19 battery is said to offer a 10% increase in capacity over the EOS-1D X's LP-E4N.
The new camera can deliver up to around 1210 shots on a full charge, compared with the original EOS-1D X's 1120. It'll be interesting to see the draining effect that activating GPS has on the EOS-1D X Mark II's battery life.
Canon EOS-1D X Mark II vs Canon EOS-1D X: 12 price
The Canon EOS-1D X's launch price was a suggested $6,799 / £5,299, and the EOS-1D X Mark II isn't too far off this - in the UK at least. Expect to pay $5,999 / £5,199 for the body only at launch.