It's been two years since Nikon launched its flagship DSLR, the D4, and like the D3S for the D3, it's time to update the D4. Enter the D4S. On the outside, the body remains mostly the same (except for the 'S'). So what changes has Nikon made under the hood?
The Nikon D4S' sensor retains the same resolution as the D4, though it comes with the new Expeed 4 image-processor for better image quality and color reproduction. The D4S is also able to shoot at extended ISO sensitivities up to an eye-watering ISO 409,600, which is one stop beyond the D4 (which is able to shoot up to ISO 204,800). Nikon has also worked to ensure that the accuracy of the camera's white balance is improved, with more vivid skin tones for subjects, even when you're shooting under different lighting conditions.
Autofocus speed has been slightly bumped, the D4S can shoot up to 11fps with autofocus and autoexposure, compared to 10fps on the D4. At 11fps, the D4S now only slightly lags behind Canon's flagship 1D X, which can shoot up to 12 frames per second with continuous AF.
There's also the new Group Area AF mode, which allows users to select a cluster of five AF points to focus on; the cluster can also be moved around. Instead of selecting a single focus point, Nikon claims this cluster will help improve focus when shooting subjects against a busy or moving background; the camera will focus on the four points close to the selected AF target for more accurate focusing.
Making movies on the D4S has also been improved. The camera is now able to shoot 1080 video at frame rates of 60p and you're also able to adjust the volume while recording. Due to the maximum file size on the FAT32 format memory cards, the D4 was only able to record up to 20 minutes of footage at 1080/30p, and we're sure that figure will drop when you're recording at higher bitrate (1080/60p). The D4S can now output uncompressed video over HDMI while recording to internal memory cards concurrently. However, the D4S is still missing other video functions like focus peaking or zebra.
Battery life has also been improved with the new higher capacity EN-EL18a battery, which allows for up to 3,020 shots per charge according to CIPA standards. The Ethernet connection on the D4S has also received a bump up to 1000BASE-T, which will appeal to photographers shooting in the studio who require fast transfer speeds. The D4S still comes with a CF and XQD card memory slot, despite nobody else picking up the XQD standard except for Nikon and one Sony pro camcorder, the PXW-Z100.
The D4S rings out as a slight update to the D4, with no single must-have difference for D4 owners to upgrade. Perhaps D3 and D3S owners sitting on the fence might finally pull out their wallets for one, but the D4S also brings with it the challenge of only having one backwards-compatible CF memory card slot and the new to buy new XQD cards (plus card reader) with the camera.