But does it actually work?
This, of course, is the million-dollar question - technology can be as conceptually clever as you like, but ultimately all that matters is whether it works in the real world. So far we've only had our hands on a non-final EOS 70D for a relatively short time, but our initial impressions are pretty positive. With the EF-S 18-55mm f/3.5-5.6 IS STM kit zoom, the camera is clearly much faster and more decisive at focusing in Live View than any previous EOS - or indeed any other SLR. We'll need to test it with more lenses in real-world shooting, but at the moment we're cautiously optimistic.
The big unknown right now is image quality - the 70D uses a 20.2MP sensor but the image is formed from 40.3M photodiodes, which is a lot to fit onto an APS-C chip. We're assuming that much of the work Canon has been doing over the past few years has been directed towards keeping noise as low as possible, and the company is confident enough to offer the same ISO range as its latest 18MP APS-C cameras (100 - 12800, with 25600 as an extended option). But ultimately the proof can only come from the images themselves.