I was looking to upgrade to the EOS M6 from the EOS 1200D/T5, but one thing that confused me was that the M6 has a listed video bitrate (at DPreview.com) at 1080p60 of 35 Mbps, and for lower framerates at 24 Mbps. Meanwhile, while I can't seem to find any actual bitrate specs for the 1200D, opening up a 1080p24 video file in Windows Explorer and switching to the Details tab under the Video section lists Data rate as 46541 kbps, with Total Bitrate just below as 48077 kbps, which if I'm not mistaken, is equal to 48.07 Mbps (division by 1000 to get Mega-bits from Kilo-bits). So how is it that the newer Canon APS-C camera has a lower bitrate with a higher framerate? Or am I just reading it wrong?
That would be a great question for Canon, because only the manufacturer can provide the reasons considered when producing a new model. I only can venture a guess that the M6 is a smaller camera that presumably is a lower-level compared to full-body T5. Maybe higher bitrate results in more heat, and the smaller body may have issues with dissipating it. Your guess is as good as anyone else's. It seems that the M6 uses the same H.264 as the prior models instead of the more efficient H.265, so seems that this is not the reason for decreasing the bitrate.