Canon has been king of the video D-SLRs with its EOS 5D II/III/IV models so there are great expectations of the EOS R which, being mirrorless, is obviously even better suited to this application.
The 4K recording is in the Ultra HD resolution of 3840x2160 pixels (there’s no 4K DCI option), but importantly now uses the H.264 codec (in the MP4 format). With UHD and FHD, either ALL-I or IPB compression regimes are available, the former enabling a bit rate of 480 Mbps with 4K, 120 Mbps with FHD. The 4K frame rates are 30, 25 or 24 fps and the 100/120 fps speeds are available with 720p HD recording for slow-mo effects. However… the big minus is that 4K recording uses a hefty 1.7x crop (as on the 5D IV) whereas FHD/HD uses the full sensor width. However, a 1.6x EF-S crop is available to match the ‘Super 35’ format. The ‘Dual Pixel CMOS AF’ is available for video shooting and both the wide coverage and very high point density should translate into superior subject tracking capabilities. C-Log gamma delivers a dynamic range of 12 stops, and other features include both HDR and timelapse recording (in 4K or FHD), digital image stabilisation (i.e. by moving the cropped image area around the sensor), timecoding and a focus peaking display. On the audio side, the EOS R has built-in stereo microphones with adjustable levels, an attenuator and a wind-cut filter. Both a stereo audio input and output are provided.