Speed demon
Is the D4s Nikon’s best-ever SLR?
The buffer capacity has increased, enabling as many as 200 JPE Gs or 176 12-bit NEFs to be captured in a burst
Since its launch in January 2012 the Nikon D4 has been the camera of choice for professional photographers who need the ultimate in speed, lowlight shooting capability and AF performance. It’s also a rugged camera, built to survive heavy use in the type of conditions that news reporters find themselves in on a regular basis.
The brand-new D4s is a relatively subtle upgrade to the D4, keeping the same pixel count and looking extremely similar, but possessing a few refinements that can be largely attributed to the move to the newer Expeed 4 processing engine.
Features
Nikon has been tight-lipped about the changes made for the D4s’s sensor, but we are told that is new and has an effective pixel count of 16.23 megapixels, while the D4’s count is 16.25 megapixels. The photosites, however, remain the same size.
According to Nikon the new sensor and Expeed 4 engine combination results in an approximately 1.5EV improvement in noise performance and this has given the company the confidence to expand the D4s’s native sensitivity setting by 1EV on the D4’s to ISO100-25600. In addition, the expanded range is ISO50-409600.
Thanks to the Expeed 4 processor, the D4s has a maximum continuous shooting rate of 11 frames per second. The D4 can manage this speed, but not the accompanied ability to focus and meter between shots. The buffer capacity has also been increased for the D4s, enabling as many as 200 JPEG Fine
quality files or an incredible 176 compressed 12-bit RAW files to be captured in a single burst. We found this was possible with a UDMA 7 CompactFlash or XQD card installed.
The D4s also has a new mirror mechanism, which has better dampening than the D4’s, to give a more stable image in the viewfinder and shorter blackout between frames. This probably explains why the camera is able to focus when shooting at 11 frames per second.
Nikon has improved the autofocus algorithms for the D4s, which uses an Advanced version of the Multi-CAM 3500AF module found in the D4. It also has Group-area AF mode, which will prove helpful when shooting subjects that are comparatively small and close to a high-contrast or distracting background.
In addition, Nikon tells us that the D4s processes images differently from the D4 as out-of-focus areas of images are treated differently from sharp subjects in order to enhance shallow depth of field.
Another, rather strange, new feature is the ability to record small four-megapixel, uncompressed 12-bit RAW files. It’s hard to image this being used very often, but perhaps those who shoot exclusively for the internet will welcome it.
Build and handling
While the change to the shape of the memory card bay door suggests that Nikon hasn’t used the same mould for the D4s as it did for the D4, most of the other changes to the design are so subtle as to be almost invisible. That’s no bad thing, however, as the camera remains very comfortable in the hand whether you’re using the horizontal or vertical grip.
The two mini-joystick-style selector controls on the back of the camera have a new, firmer, finish and it makes them easier to find and use when wearing gloves or shooting
in the wet. They are also easier to identify when the camera is held to the eye than the rubber-topped controls on the D4.
Just like on the D4, the vertical shutter release is a little recessed into the body. While this button is still easy to reach, it makes the front command dial less prominent than the horizontal one and it’s harder to find with your finger.
Other controls fall within convenient reach and are as responsive as you’d expect with a professional-standard SLR.
Being an SLR, the D4s has an optical viewfinder, and it’s a great one, showing 100% of the scene and being large and bright. As usual, when a DX lens is mounted on the camera, the area outside the automatic cropping is dimmed so it’s easy to compose images.
While the 3.2-inch 921,000-dot LCD on the back provides a nice clear view and displays colours accurately, it does suffer from reflections in bright conditions.
Peripheral AF is more responsive and the new Group-area AF mode does an great job of keeping a moving subject sharp
Performance
The D4’s AF system is no slouch, but the D4s’s raises the game even further. The peripheral AF points seem a little more responsive and the new Group-area AF mode does a great job of keeping a moving subject sharp. However, apart from the number of points involved (five in Group-area AF) it’s a unclear how this differs from the nine-, 21- and 51-point dynamic-area AF modes.
While the Matrix metering system copes well with ‘average’ and bright scenes, there is a slight (and understandable) tendency towards overexposure with some scenes that are intrinsically dark in tone. It’s not a major issue and it only seems to occur in those conditions in which a professional photographer might anticipate it.
Although a pixel count of 16 million maybe comparatively low by modern standards, especially considering that Nikon is now using 24- and 36-megapixel sensors, the D4s can resolve an impressive level of detail, which is maintained a little better throughout the sensitivity range than the by the D4. There’s also little sign of noise throughout the native sensitivity range, although higher-ISO JPEGs look slightly smoothed at 100% on screen.
Of course the burning question that the D4s raises is, what does an ISO409600 image look like? The answer is: pretty terrible. Even at small viewing sizes there is banding visible in the JPEGs, and at close scrutiny they have a cross-hatched pattern. The RAW files look a little better, but there’s still some banding. However, this is not a sensitivity setting for everyday use, it’s designed to be used by pros reporting important events in near darkness.
Interestingly, the lab test figures for signal-to-noise ratio indicate the D4s falls short of the D4, but it does produce sharper detail in the midhigh ISO range, which is a trade-off most users would be happy to accept.