Nikon just announced the features of its new premier DSLR, the Nikon D4S. We caught a glimpse of the new D4S in January at CES 2014, but this is the first time we have been able to take a look at the specifications.

The D4S looks very much the same as the D4 on the outside. On the inside, the D4S presents some refreshing upgrades to the older D4 that action shooters will appreciate.

photo by Henry Söderlund

Image Processor

The new EXPEED 4 Image Processor is at the top of the improvement list. First seen in the D5300 last year, the EXPEED 4 is responsible for a host of upgrades in the D4S. The most noticeable benefit is improved ISO range and performance. The D4S tops out at an unheard of ISO 409,600 (at the Hi4 ISO setting).

Nikon also claims that low light noise at ISO 1600 will be identical to the performance of the D4 at ISO 800.

Shooting speed and processing time are also improved. The EXPEED 4 has 30% more processing power than its predecessor. You’ll notice the improvements in image buffering. The D4S should be able to shoot 200 full-size JPEG images before the buffer gets full. A massive image buffer is helpful, because Nikon increased the frame rate of the D4S to 11 frames-per-second.

Autofocus

Autofocus improvements will make the D4S a noticeable upgrade for action photographers. The D4 could shoot at 11 frames-per-second, but only with fixed exposure and focus. The D4S promises to provide continuous focus at the highest burst frame rates.

The D4s does not have a new autofocus sensor. The real system behind the upgrade is a new mirror-moving mechanism. The amount of blackout time in the viewfinder while shooting bursts was reduced, allowing autofocus for longer periods of time.

A new five sensor group autofocus mode also claims to boost performance. This feature allows you to choose a five point cluster of focus points. It will be interesting to see how this feature works in practice, as the old focusing system was similar. The difference is that the D4S weighs the autofocus points next to your selected target differently.

Movie Shooting

The D4S might disappoint videographers. Relatively few improvements were made to video shooting functions. Nikon touts the camera’s ability to shoot 1080p video at 60 fps, which is a noticeable upgrade from the D4.

Video capture time, however, is where the D4S and D4 suffer. The D4 hits a 20 minute video recording limit. The D4S tops out at 10 minutes while shooting at 1080p and 60 fps.

The D4S will allow ISO adjustments during video shooting. It can also output video over HDMI and record to a memory card at the same time. Disappointingly, it lacks many movie making features found on other DSLRs and even mirrorless shooters. It doesn’t offer focus peaking or a zebra pattern to aid in exposure.

Conclusion

Comparing spec sheets, the D4S improves the D4 platform at almost every point. ISO performance (a massive 409,600 ISO), autofocus improvement, and image processing power are the real updates.

The Nikon D4S offers a variety of additional updates that I didn’t discuss in detail: Ethernet output has been increased to 1000MBps for faster tethered shooting, top active D-lighting has an “Extra High 2” setting, and Nikon claims that autofocus algorithms were updated.

These are somewhat small bullet points compared to the new EXPEED 4 and mirror mechanism.

For action photographers who need a massive image buffer and better AF performance in burst mode, the D4S is an easy upgrade. Personally, unless I was craving massive resolution, the D4 was already an excellent camera. The only real complaint I had was poor battery life—something that Nikon solved with an updated 2,500 mAh battery in the D4S.

The D4S is worthy of being at the head of the class. With improved autofocus, burst fire speed, already legendary low-light performance and better buffering ability, it’s a fair challenger to the Canon 1DX.

You can order the Nikon D4S on Amazon.