The Rebel T4i is the first Canon DSLR to feature full-time AF in video mode. The past Canon DSLRs have featured the ability to force an AF confirmation using a slow and clunky contrast-detect method, which was simply unusable during video capture. Another AF confirmation option has been to use the cameras’ phase detection sensors; however, this caused a blackout during live view thanks to the mirror flipping down in front of the image sensor.
The folks over at Chipworks [via Image Sensors World] tore down a Rebel T4i to get a look at the image sensor and reveal phase detection sensors mixed among the pixels. This is something that Canon has been cooking on for a while. (Note this patent application that I discussed back in 2010.)
And while we’ve seen this concept implemented in prior cameras (notably the Fuji F300EXR point and shoot camera and Nikon 1 Series), Canon has gone about it in a technically different way to make it effective for DSLRs. [Read more...]