A $5000 camera is not within reach for most people. So this Nikon D3s review is a bit different—it's a peek at the near future of photography where shooting in any lighting condition is possible. It's really exciting.
ISO Is the New Megapixel: A Case Study

Nikon effectively declared the pixel war over with D3 two years ago: Its $5000 flagship shot a mere 12 megapixels—less than many point-and-shoots—and began the low-light arms race. The D3s again forsakes more megapixels for more light, sticking with 12 megapixels, and it's a tiny miracle of engineering.
The D3s isn't a thoughtless product rehash—as you might expect given that Nikon's simply tacked an 's' onto the end of the D3. Unlike the D300s, which didn't progress all that far in the two interceding years, the D3s is steady evolution at its best: It offers roughly double the low-light performance as the original D3.

What All This Low Light and ISO Business Means

A brief explanation of low-light digital photography and ISO is in order (click here for the long explanation). The focal point of engineering with the D3s, and other cameras of this caliber, has been boosting their ability to pick up more light (because a photo = light). That photo directly above with a 100 percent crop in the loupe? Taken at night at ISO 102,400.
The D3s uses a completely new sensor that refines elements of the original D3's sensor, like a new gapless microlens architecture that directs more available light onto the sensor's photodiodes. With film, ISO speed is a standard that indicates how sensitive the film is to light—higher speeds are more sensitive. With digital cameras, when you set the ISO speed, it's supposed to be equivalent to the film standard. In low-light conditions, you boost the ISO, so you don't need a long exposure time or wide open aperture. The problem with cranking up the ISO—is that when you boost the camera's sensitivity to light (the signal) you're also boosting its sensitivity to noise—which can be sexy with film, but isn't really with digital photos. The D3s shoots up ISO 102,400, far beyond any film you could buy at Walgreen's. (Does Walgreen's still sell film?) At that level, you're talking night vision, practically, though the resulting noisy ass photo's nothing you'd want to print.

So, here's what the D3s offers, practically. In the most common DSLRs that people own, or with the latest crop of Micro Four Thirds cameras, the borderline for what we'd call good ISO performance is around ISO 800. In the original D3, it was ISO 3200, orders of magnitude better.
The D3s doubles the low-light performance of the D3: ISO 6400 photos look just about as clean ISO 3200 photos taken with the D3 (they look good), and ISO 3200 photos are whistle clean to all but the most trained eye, especially if they're down-res'd to web or print size. ISO 12,800 is the new ISO 6400—the outer limit of acceptably printable. In short, the D3s is the best low-light camera we've ever used, a leap beyond last-generation's low-light killers. You can basically shoot in any lighting condition. That's incredible.

It's Built for Photographers

The D3s is built for war zones, and being slung in the mud at 40mph. It weighs nearly 3 pounds, without a lens. Yet it's well-balanced and supremely comfortable to hold, with the best ergonomics in its class—Canon's 1D Mark IV feels surprisingly awkward by comparison—so we could shoot for hours on end in the closest thing to gadget blogging's war zones, CES and the iPad launch, and slug people who got in our way. (The dual CF card slots and ginormous battery help with shooting for hours. We didn't quite reach the 4,200 shots it's spec'd for, but we definitely shot a couple thousand photos per charge.) It feels like what a pro camera should feel like, with almost all of the controls you need at your fingertips—the addition of a dedicated live view button versus the original D3 definitely helped there, though a more natural way to change the ISO setting while using the camera's vertical grip would be nice.

It is a photographer's camera, though, to be sure. Even as it shoots a crazyfast 9 frames per second at full-resolution RAW and its 51-point autofocus proved fast and accurate for us at trade shows, Nikon continues to lag behind Canon when it comes to video, with it feeling more tacked on than any of Canon's shooters—it's still 720p video using the bleh Motion JPEG codec—it's functionally better than the D300s, though, with improved autofocus in live view mode. That said, given that Nikon's announced its first 1080p-shooting camera, we're hopeful for the seemingly inevitable D700s on the video front, anyway.
Most of our testing took place at CES and the iPad event, which are marked by $#@!ty and ever-changing light conditions, and we've never felt more comfortable shooting handheld without a flash or tripod. It's truly liberating. Light is your bitch—you can shoot wherever, whatever you want. (Especially with a fast lens, but even "slow" lenses suddenly feel eminently more usable.) While auto white balance was never quite perfect, the pop and saturation of the D3s's colors are just about unbeatable. It's the ultimate gadget-shooting-in-crappy-conditions camera. Here's some of posts we used the D3s to shoot:
• iPad Hands On
• iPad Liveblog
• Slayer Espresso
• E-Ink Is Dead, Pixel Qi Just Killed It
• Ballmer CES Keynote
• CES We're Here
(You can also check out our previous hands on with a pre-production unit for more samples.) A note: You'll notice I don't have a ton of sample photos, and that's because somehow hundreds of them completely poofed.

The D3s doesn't operate under any new philosophy, but it does remarkably take the game a step further, revealing with more clarity a world where camera performance doubles roughly every two years if we can use some restraint on the megapixels. (After all, newspapers and monitors are only so big.)
We're running through Canon's answer to the D3s, the 1D Mark IV at this very moment, so we're intensely interested to see who's wearing what pants at the end of this. Either way, it shows that competition is a very good thing: Everybody wins.
The best low-light camera we've ever used
Fast and accurate 51-point AF to go with its 9FPS rapid fire
Solid ergonomics
Would prefer a more accessible ISO button
There's still a major disconnect with video, which lags behind Canon quality and otherwise
It's $5000, so this amazing low-light performance is out of reach for most people for a few more years (not really a knock against the camera, just a general frowny face)[Nikon]

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