Nikon D4S Review

The Nikon D4s is among the most feature-rich digital cameras ever built, taking on the incredible feature list of its predecessor and refining a number of them. Both these cameras offer functions which are unique between them which you can read about in the Capability page of the D4 review.

The two major changes of the D4s are a new image-sensor and faster EXPEED 4 processor. The revised 16 megapixels CMOS sensor offers a standard ISO sensitivity range up of 100 - 25600. It also supports expanded ISO 50 and 51200 to 409,600 which is unprecedented. Only one other digital camera has been announced with that sensitivity which is the Sony Alpha A7S
Sony Alpha A7S full-frame mirrorless.

The EXPEED 4 processor delivers faster performance. Together with a newly-revised mirror-mechanism which reduces black-out time, this lets the D4S maintain full autofocus and auto-exposure while shooting at 11 FPS. Buffering has been improved to allow up to 200 JPEG images at maximum image-quality or up to 78 losslessly-compressed RAW files at maximum bit-depth.

Nikon has a tradition of offering various types of RAW files and, this time, they added one more. First, just like most Nikon full-frame models, there is a choice of 14 or 12 bits. The former allows more color gradation and nuances, while using slightly more storage. While both are RAW files, which only contain one channel per pixel, the latter obviously loses some data which means should not be considered truly RAW but unprocessed. There is a choice of compression, including none, lossless and lossy. This last option saves space at the expense of image-quality but far less than JPEG compression.

The Nikon D4s adds a new Small RAW format which offers an entirely different image-quality compromise. It is, however, heavily processed to produce an 8 MP file with 12-bits per component in YCbCr format. This gives an image with a luminance channel plus deltas along the Blue and Red direction to determine colors. In practice, this is much closer to a JPEG with extra-bit-depth than what is typically known as RAW sensor data.

This DSLR provides the most advanced Interval-Timer feature of any digital camera. It can now capture 9,999 images automatically. The interval between frames can be set between 1 second and 24 hours. Up to 9 frames can be captured at each interval which makes it possible to bracket for exposure throughout the capture period. Shooting can start immediately or up to one week later. Previously, the maximum delay was 24 hours.

New to the Interval-Timer and Time-Lapse Video is an Exposure-Smoothing option. When enabled, instead of metering each frame completely independently, the D4s tried to make transitions between successive frames smoother. When assembled into a time-lapse, this results in a smoother video. One example is when shooting moving traffic. As cars pass, the metered exposure can vary greatly.

Video

Full 1080p HD video has been possible on Nikon DSLRs for a while. This one adds a number of improvements over previous generations. It can record 1080p at up to 60 FPS, with 50, 30, 25 and 24 FPS available as options. This can be output as a clean 1080p signal over HDMI while simultaneously recording onto a memory card with Quicktime format and H.264 codec.

Considering that even full HD video only requires 2 megapixels, the D4s allows video to be captured from a cropped-area of the sensor. FX (Full-Frame), DX (APS-C) and 2.7X (Nikon 1) crops are all selectable during Live-View.

Audio has been enhanced too. The recording levels can be adjusted during filming and the frequency-range of the built-in microphone can be optionally tuned for voices. There are still mini-jacks for stereo input and output. Video capture allows full manual-controls, including Auto ISO in Manual mode which lets the camera film with a constant aperture and shutter-speed while maintaining the metered exposure. Expanded sensitivities, up to ISO 409,600 are possible but not ISO 50 or 100.

Time-Lapse video uses current Movie settings which makes it possible to play back at up to 60 FPS, although twice the number of source files are obviously needed for the same length of video.

Body

Physically the D4s looks nearly identical to the D4. It somewhat heavier at 1350 versus 1180 grams. While this is a non-trivial increase, the difference is hard to notice when a quality lens is attached. Controls to the right of the LCD were slightly reshaped. Both joysticks now have a texture to improve traction and usability with gloves. The 8-way controller feels stiffer and a little harder to move though.

While the network port looks the same, it is 10X faster than before, offering Gigabit Ethernet now. USB remains at 2.0 which seems slightly behind times. Nikon still has not decided on a memory-card type as D4s continues to offer asymetric slots. One is Compact Flash Type 1 and the other is XQD. We hope to see a pair of identical slots on the next model.

The new 16 megapixels sensor and EXPEED 4 processors at the heart of the Nikon D4s are less power-hungry than their predecessors. This lets the D4s reach a whopping 3020 shots-per-charge, compared to an already stellar 2600 according the the CIPA standard.