Much has been made of the upcoming Canon 70D’s new autofocus system. Panasonic’s been working on its own revolution in autofocus. But where is it?
Although advance reports of the Canon 70D claimed a July release, it has only now become available and is in stock in stores including Amazon, B+H and Adorama.
Canon 70D leap forward for autofocus
Formerly, DSLR autofocus systems employed contrast detection, which may be serviceable for still photography, but is pretty much unusable for video recording. Even newer DSLR cameras that advertise phase detection are really phase and contrast detection hybrids. The 70D boasts an innovative dual pixel phase detection scheme, in essence splitting each photodiode in half. An algorithm compares each half’s light data, in addition to the full photodiode’s image data, to make its focus adjustments. As opposed to hybrid methods, which require separate phase and image passes, the 70Ds system needs just a single pass to achieve focus. The result is a much quicker and accurate system, without the jittery, back-and-forth behavior that’s probably familiar to anyone who has used DSLR autofocus.
Panasonic’s autofocus system looks great, on paper
If the Canon 70D’s autofocus performance is as good as advertised, the company will undoubtedly please its fans and win converts. It shouldn’t be a surprise that Panasonic has been working on its own phase detection autofocus system. According to 43rumors.com and this patent, Panasonic’s system is very similar to the Canon system, with a subtle difference: instead of halving each photodiode, the Panasonic system utilizes completely separate layers of photo sensors for phase detection and image detection. However, it remains to be seen if this system is better or worse than the Canon system, since Panasonic’s next level autofocus system is, well, currently just a patent.
Digging a little deeper, we discovered a patent filed in 2010 which appears to be Panasonic’s first thoughts on phase detection autofocus. It’s interesting that they were investigating phase detection three years ago, yet the GH3 doesn’t even use hybrid phase detection for its autofocus, relying on an ‘advanced’ contrast detection system instead. While it’s possible that Panasonic’s new compact DSLR, the Lumix GX7, will feature this advancement, we haven’t heard any such grumblings. It’s more likely that fast phase detection autofocus will have to wait for a GH3 successor.