July 2, 2013 at 3:23 PM ET
The latest mid-range DSLR camera from Canon solves the years-old and industry-wide problem of providing fast and accurate autofocus while shooting video. By rethinking how the entire sensor works with the new 70D, Canon has jumped to the front of the video-enthusiast camera pack.
For decades, cameras (even non-digital ones) have used "phase detection" as their autofocus method. Those little squares in the viewfinder indicate the special two-part sensors that detect light coming from different parts of the lens and use that to determine whether the subject is in focus, or how to get it in focus.
Phase detection has always worked like a charm, but the way it was implemented meant that either it wasn't available during video (in which case slower "contrast detection" must be used), or during low-light situations.
Instead of scattering a few phase detection sensors around, which the standard method, Canon made every pixel on the sensor into one. This means the system can be used at full effectiveness in almost any light and while shooting video or in live view as well. Canon describes it here, and enthusiast site DPReview.com has a more technical explanation here.
Apart from its unique and powerful new autofocus, the 20-megapixel 70D is a powerful but familiar camera. Its design is very similar to its predecessor, the 60D, with a high-resolution flip-out LCD and the usual dials and buttons. It also has Wi-Fi built in, so you can use wireless accessories or tether the camera to your computer or phone.
It inherits a touchscreen from the more entry-level Rebel cameras, which implemented it quite well. You can tap to set autofocus targets, and have it "slide" between the two during filming.
Many home video fanatics and filmmakers on a budget will no doubt find the 70D irresistible, though the $1,199 price will turn off less serious shooters. But good things tend to come to those who wait, and the powerful phase-detection sensor will in all likelihood come to some of both Canon's cheaper and more expensive bodies. In the meantime, the 70D will be available in September.
Devin Coldewey is a contributing writer for NBC News Digital. His personal website is coldewey.cc.