By site editor Dan Chung:
The 7D mkII may not be much of a revolution in video image quality – by all accounts it is very similar to its sister the 5D mkII but with a smaller sensor. But as I previously highlighted, the one new feature that the camera has that may turn out to be a significant technological advance is the new speed adjustable video autofocus system. Essentially the same Dual-Pixel CMOS AF system found in the 70D and optionally on the C100 and C300, Canon engineers have added the ability to control how fast the AF adjusts to a change in focus point. You can select a slower, more graceful focus pull, or a faster one to get you there in a hurry.
You can see how this works in the video review by Larry Becker of Kelby One for B+H. About half way through he shows a clip of the system working. Although the clip isn’t very long it does amply demonstrate the potential. Becker does point out that the 7D mkII doesn’t have the focus via touch screen that is so useful on the 70D. This is a real shame because changing the focus point on the 7D mkII requires toggling with buttons – far less usable than touch focus. Without the touchscreen I don’t think the full potential of the speed adjustable focus can be realised. You can I believe achieve something similar using Canon’s remote software connected on tablet or computer connected via USB – but this is nowhere near as convenient. So for the 7D mkII this is an opportunity missed.
Still, what is significant to me is that Canon clearly have this technology at their fingertips and, if they choose, they can put it into their next generation of Cinema EOS cameras. They have been long-time leaders in the field of AF technology and their EOS line of lenses are better suited to the task of video AF than other manufacturers. Their STM line of quieter, smoother lenses has also been increased lately, and non STM lenses like the 35mm f2 L IS are also getting quieter. I think we can expect to see quieter, smoother professional lenses at some point soon.
Sony’s FS7 has all the latest 4K technology and great ergonomics – but I don’t expect the autofocus system to rival the C300. Autofocus is the one area Canon could comfortably maintain an advantage. Lets see what next year brings.
Edit: below is a video from Canon that is shot using the 7D mkII and the speed adjustable AF: