Fujifilm X-T1 Firmware Ver.4: Zone and Wide Tracking focus modes
The new Zone mode works well for continuous focusing on oncoming subjects
The main additions in Firmware 4.0 revolve around autofocus. Two new modes have been added to help deal with moving subjects, namely Zone and Wide Tracking, both of which employ a 77-point grid of focus areas covering almost the entire frame. In Zone mode, you can specify a group of focus points – either 5×5, 5×3, or 3×3 – and position it freely within the frame. This is ideal for subjects moving predominantly towards, or away from the camera.
In Tracking mode the camera can use almost the entire area of the frame for focusing. You can set a specific point for the initial focus acquisition, but once the camera has locked on to the subject, it will attempt to follow it around the frame. In principle, this should be a better choice for more erratically moving subjects.
Fujifilm X-T1 + XC50-230mm f/4.5-6.7
In practice, things are a little more complicated. The X-T1’s X-Trans CMOS II sensor has phase detection elements in the central region of the sensor allowing fast focusing, but if the subject is outside of this area, the camera has to revert to the slower contrast detection AF. This requires the sensor to be read between exposures, so is limited to working at in the slower CL shooting mode, which has a mximum shooting rate of 3fps. The upshot of this is that, if you want to shoot fast moving subjects, you’ll need to use Zone mode and the 5×3 grid of PDAF-capable focus points in the centre of the frame.
I tried out Zone mode shooting fast-moving planes, using the XC 50-230m f/4.5-6.7 telezoom, which is Fujifilm’s longest X-mount lens. I found that it worked well, keeping subjects moving quickly towards the camera in focus most of the time. The key advantage of zone mode is that it’s no longer necessary to keep a single AF point over your subject, which is tricky at the best of times. It’s worth noting that the shooting rate will often drop significantly below the maximum 9fps, as the camera needs a fraction of a second to refocus between frames. It’s also necessary to set the camera to use the mechanical shutter only (Shooting Menu 5 – Shutter Type – MS); otherwise it will shoot at full speed with focus fixed.
Fujifilm X-T1 + XC50-230mm f/4.5-6.7
With Tracking mode the results are a little more equivocal. It works well when the subject is easy for the camera to identify, for example as a solid block of strong colour, and moves around the frame relatively slowly. But like similar modes on other brands, it can get laggy and confused when the subject moves too quickly, or is too small for the camera to easily distinguish from the rest of the image. It can certainly be useful, but it’s far from foolproof.
So while Firmware 4.0 brings useful and welcome advances, the X-T1 still has a way to go to catch up with the very best AF systems around when it comes to moving subjects. Notably, the phase detection area covers a relatively small part of the frame compared to DSLRs like the D7100 or Canon EOS 7D Mark II, or premium CSCs like the Samsung NX1 or Sony Alpha 6000. I also found that the system was far too keen to refocus when another object briefly came between the subject and the camera, and took a few frames to reacquire focus afterwards. Most enthusiast DSLRs are a bit more intelligent in understanding such a scentario, and holding off from refocusing.
