Nikon D4

Bottom line

Any photographer would probably be ecstatic to own a Nikon D4, experts say. It shoots spectacular images -- even rapid-fire or in dim light -- and it's built to take all of the daily abuse a pro can throw at it. But the Canon EOS-1D X (*Est. $6,780 body only) proves just a little speedier, just a bit quicker to autofocus and just a little better in low light. Still, the differences are pretty small. If you're married to a bunch of Nikon lenses, "it's probably not time for a divorce," says TJ Donegan at DigitalCameraInfo.com.

Ease of use

Backlit buttons make it easier to shoot in the dark. Like its Canon rival, the Nikon D4 is enjoyable to shoot with, according to critics. Both cameras are bulky and heavy, with the Nikon weighing more than 2.5 pounds. Yet reviews say they're comfortable whether you hold them vertically or horizontally due to their thick grips on both the bottom and side, plus two joystick controllers.

Both DSLRs have viewfinders that show 100 percent of the scene, plus big 3.2-inch LCD screens to compose shots in Live View. Lightning-quick file transfer is possible thanks to fast Ethernet ports.

The Nikon's one new extra is backlit buttons. "One of the D4's most useful features is also one of the simplest," says Richard Sibley at Amateur Photographer. Angela Nicholson at TechRadar.com agrees that the lighted buttons -- which are just bright enough to read -- make shooting in the dark "much easier."

Performance

Slightly slower and lower-res than the Canon. The EOS-1D X just ekes past the Nikon here, although the latter holds the edge in video. The Canon boasts a higher resolution of 18.1 megapixels versus the Nikon's 16.2. While both full-frame cameras can shoot at an exorbitant ISO 204,800, the Canon's high-ISO shots look clearer in tests at TechRadar.com.

But Canon's main advantage is speed. The Nikon D4 can fire off at 11 frames per second (fps), but the 14-fps Canon is faster. "It's possible that 14 fps could make all the difference when attempting to photograph split-second action," says Amy Davies at TechRadar.com. "It's the 1D X that wins in the shooting speed stakes."

Both cameras offer lots of autofocus points -- 51 for the Nikon, 61 for the Canon -- but many more of the Canon's are cross-type, and testers say they're spread out better over the frame. However, more of the Nikon's autofocus points will work at slim apertures down to f/8, which is important for wildlife photographers who use telephoto lenses with teleconverters.

Reviews say both cameras' full HD video looks great, but the Nikon D4 does a couple of things the Canon doesn't. You can ship uncompressed footage straight out of the Nikon via HDMI, and the camera has a headphone jack for monitoring audio as you record. "If you need a device that does stills and videos at a pro level with pro-level control, the D4 is the best we've seen to date," says DigitalCameraInfo.com's Donegan.

The Nikon D4's battery life is 2,600 shots per charge, much more than the 1,120-shot EOS-1D X.

Durability

Built pro tough, like its Canon rival. Both the D4 and EOS-1D X are built to withstand years of professional toil. "In many ways the Nikon D4 feels very solid and likely to stop a bullet, should the need arise," says TechRadar.com's Nicholson. Like the Canon, it has a weather-sealed magnesium body and a shutter designed to last for 400,000 shots.

"For a professional photographer shooting around 2,000 images a week, the shutter is good for four years. For the rest of us, it will probably last a lifetime," says Sibley at Amateur Photographer.

Nicholson's D4 tester had a jiggly memory-card door, with a cover over the door lock that "seems a little flimsy, and it feels like it could be wrenched off fairly easily by over-enthusiastic use." When she later tests the Canon EOS-1D X, she says the whole camera -- and specifically these two areas -- feels perfectly solid.

Features

XQD memory cards -- love 'em or hate 'em. Critics are split over the Nikon D4's brand new memory card format. It's the first new DSLR with an XQD slot alongside the regular Compact Flash (CF) slot. XQD is faster but pricier. A 32 GB XQD card costs about $230, about $100 more than a top-quality CF card the same size, plus about $45 for a new card reader.

Some reviewers very vocally wish that Nikon had just stuck with two CF slots, as Canon did, since pros generally already own a stack of CF cards. But others applaud Nikon: "Professionals who are going to take long bursts of images should seriously consider switching to XQD cards," says Amateur Photographer's Sibley after an XQD card cleared his buffer more swiftly. TechRadar.com says the XQD slot makes the Nikon D4 more "future-proof" than the Canon.

A Wi-Fi transmitter comes standard on the Nikon D4; the EOS-1D X charges $600 extra for one. The transmitter lets you see images in Live View on your iPad, plus set the autofocus point and shooting mode and trigger the shutter remotely. "This is something else that is likely to appeal to wildlife photographers who may want to sit remotely from their camera," says TechRadar.com's Davies.