As you would expect for a professional-grade DSLR overall build quality is excellent; the D4 is an incredibly solid piece of kit that’s purpose built to stand up to the rigours of daily use. Encased within a magnesium alloy cage the D4 is also fully sealed against moisture and dust penetration along with electromagnetic interference. That said we were somewhat surprised to find that – at 1340g – the D4 body is actually a bit lighter than the D3s.
The large rubberised handgrip of the D4 provides a comfortable and secure grip, although given the size and weight of the D4 it does require two hands to operate. Controls are well laid out and fall within relatively easy reach, which helps to make shooting with the D4 an intuitive and enjoyable process. While the general control layout of the D4 follows on from what was found on the D3s, there are a few changes of note – especially with regards to the controls immediately available when the camera is being held in portrait orientation. The main difference here is that the D4 gains a second multi-selector (for control over AF point selection and suchlike) that falls within range of the thumb, while the AF-On button has been repositioned to sit next to it. A thumb grip has also been added which makes holding the camera in portrait mode more comfortable.
One other notable difference on the back is that whereas the D3s offered a single LiveView button with could be used to toggle in and out of Live View, the D4 offers a two-way switch that allows you to toggle directly between stills and video capture. One further difference is that the AF/M switch on the front of the camera no longer enables you to switch directly between AF-S and AF-C. Instead, you have to press the button in the middle of the switch and then use the front command dial to switch between the D4’s various AF modes and the rear dial to toggle between AF-S, AF-C and AF-A. One final touch worth mentioning is that the buttons on the rear of the camera can now be illuminated, making the camera much easier to work with in low light.
In terms of performance the D4’s 51-point AF system improves over what was found in the D3s to offer one of the very best AF systems going, if not the best. Used in AF-S mode, focus is not only lightening fast in good light but remains impressively quick when light levels drop too. Given that the D4 is likely to find favour with news and sports photographers shooting moving subjects AF-C is likely to find regular use too, and thankfully it doesn't disappoint. Working alongside the D4’s Advanced Scene Recognition System and utilising the new 91,000-pixel metering system, you can opt to use nine, 21 or all 51 of the D4’s AF points in Dynamic AF mode. In addition, the camera also offers 3D Focus Tracking, which is essentially a predictive system that will track your subject across all of the 51 available AF points.
Using the D4 in Live View mode switches the focus method from phase detection to contrast-detect AF, with choice of either AF-S or AF-F. The latter option offers full-time servo AF where autofocus is constantly adjusted should you or your subject be moving, and in addition there are also four AF modes to choose from: Face-priority AF, wide-area AF, normal-area AF and subject-tracking AF. While the D4’s contrast-detect AF system isn’t quite as snappy as some recent compact system cameras are, it's still pretty responsive.
While the 10fps maximum continuous shooting speed (with constant AF) of the D4 isn’t quite as quick as the Canon 1D X’s 12fps maximum burst rate, it is on a par with the Sony A99. And just as the 1D X offers an extended 14fps ‘High Speed’ (JPEG only) burst mode so the D4 also offers an enhanced 11fps option – although in order to gain the extra frame the camera does have to lock focus on the first frame in the sequence. Shooting at 10fps and using an XQD card, the D4 is capable of shooting a mightily impressive 75 Raw files at full speed before the buffer fills and slows the camera down – something that completely outclasses the D3s's 33 Raw files at 9fps capabilities. As for JPEG capture, we were still shooting at full speed after reeling off 100 consecutive full-resolution shots with no discernable slowdown.
The slightly larger 3.2in screen on the back of the D4 is bright and sharp and extremely usable in both Live View mode and for reviewing images with. Putting the camera into Playback mode it’s possible to review your images using the separate zoom in and zoom out buttons to check edge sharpness and fine detail. The in-camera menu is extensive and offers numerous ways to customise and set-up your camera exactly how you want, it remains intuitive and easy to navigate.