Sony’s latest APS-C mirrorless features some remarkable technology, says Andy Westlake, but is let down by its out-dated body design.
Sony Alpha 6400: Autofocus
If you’ve read this far, you’ve probably concluded that I think the A6400 is an absolute stinker of a camera. But it’s more complicated than that, because the A6400 incorporates an absolutely ground-breaking autofocus system that’s far ahead of anything else I’ve previously used, including Sony’s own flagship Alpha 9. This is, to put it mildly, a really big deal, particularly if you regularly shoot moving subjects.
Sony’s new AF system leaves its rivals trailing with its new Real-Time Eye AF and Real-Time Tracking technologies. In essence, these use a wide range of information, including colour, pattern, shape and distance, to lock onto the subject and then follow it wherever it moves around the frame. All you have to do is enable AF-C and Tracking modes, then place the focus area over the subject and activate AF. The camera will do the rest. It advances on previous subject-tracking systems by its uncanny ability to keep track of the designated target almost no matter where or how it moves, or what obstructions pass between it and the camera. It can even re-acquire the correct subject if you temporarily lose it off-screen.
When shooting human subjects, the camera is also able to switch seamlessly between eye-detection, face-detection and simple object recognition if your subject turns their face away. What’s more, you don’t need to assign a custom button to activate Eye AF any more; instead it kicks in automatically if you use the shutter or AF/MF buttons to activate autofocus. If you shoot human subjects for anything other than static portraits, this has the potential to completely transform how you work.
That’s not the limit of the system’s usefulness, however; it has the potential to change how you use autofocus completely. Even with static subjects, it’s possible to change composition while the camera keeps track of your main subject, so you don’t even have to move your focus point around the frame manually. You might think that this sounds little different to the conventional focus-and-recompose approach, but it’s not susceptible to the same errors as the camera focuses on the subject after it has been placed off-centre, rather than before.
If this all sounds too much like science fiction, you still have a full set of conventional AF modes to fall back on. You can choose between various sizes of focus area, and move the point of interest feely around the frame using either the touchscreen or the d-pad, although the latter requires a custom button to be assigned to the obscurely-named Focus Standard. I’d recommend using the touchscreen, if you can live with it, as the focus area is then highlighted in a readily-visible orange when you move it. However when you use the d-pad, the focus area is outlined in a near-invisible grey, so it’s often impossible to see. This is a long-running bug that Sony shows no sign of fixing.