The Nikon D810 is the successor to both the D800 and D800E. However, because those cameras only had minor specification variations, we'll deal with them as one camera for the most part – highlighting any differences when they occur. As the cameras only have minor physical differences, it's probably worth pointing out that the D810 is on the left in our graphics, leaving the D800/E on the right.
There isn't a single difference in the sizes of these cameras. They are just as big as you would expect of a full-frame professional-level DSLR.
The D810 and its predecessors are all weather and dust sealed, meaning you shouldn't have to worry about using them in all but the most extreme conditions. Magnesium alloy construction also means they are as sturdy as you would expect for this calibre of camera.
The D810 is a bit lighter, but only by 2 percent. The figures above are when the cameras are loaded up with a battery and SD memory card, but no lens.
While all three cameras feature an effective 36.3 megapixel full-frame CMOS sensor (35.9 x 24 mm), there are a number of key differences. For example, the sensor in the D800 uses an optical low-pass filter (OLPF) to help prevent moiré and false color, while the D800E removes its effect to deliver sharper and more detailed images. With the D810, Nikon has decided to do away with the optical low-pass filter altogether, and its all-new sensor is said to produce even more detailed images and video.
Nikon says its new Expeed 4 image-processing engine, which was also deployed in the flagship D4S, is 30 percent faster than its predecessor. In addition to speeding things up, the new image-processing engine is said to deliver impressive tonality, and reduced noise across all sensitivities.
Both generations of big megapixel full-frame DSLR feature the same Multi-Cam 3500-FX AF system with TTL phase detection, which uses 51 focus points, 15 of which are the faster cross-type. However, the D810 boasts updated AF algorithms to make it even more precise, even in challenging light conditions. The new camera also gains the Group AF mode which we saw in the D4S. This offers enhanced accuracy while tracking subjects, by using five focus point, one selected by the user and the four around it.
These cameras are never going to break any speed records when it comes to continuous shooting. That said, Nikon has upped the maximum full-frame frame-rate from 4 fps in the D800/E to 5 fps in the D810. As before, if you want to get the maximum shooting speed out of the camera you'll need to shoot in DX crop mode and be using a battery pack. Doing this, the D810 can fire off a respectable 7 fps, compared to the D800/E which peaked at 6 fps.
The combination of new sensor and new image-processing engine means the Nikon D810 has a significantly wider ISO range than its predecessors. Its native ISO range of ISO 64-12,800 means it should produce better images whether shooting in a well-lit studio, or in a lower-light situation. It can also be expanded to ISO 32-51,200 equivalent if the need arises.
Some had expected the follow-up to the D800/E would make the jump to 4K video recording. However, the D810 actually just gained Full HD 1080p recording at 65/50 fps. But resolution isn't all that matters when it comes to video, and the D810 builds on the D800/E, which boasted video credentials like clean HDMI output, microphone input and headphone output.
New video features include an Auto ISO in M exposure mode, which eliminates the need to adjust the aperture, a highlight-weighted metering option to help prevent blown-out highlights in video, and the addition of zebra stripes to make it easier to spot overexposed areas while filming. A new flat/neutral color profile is also especially handy when shooting video as it gives users maximum flexibility in post-production. The built-in microphone on the D810 is also stereo.
Both generations of camera feature a large optical viewfinder which offers 100 percent frame coverage and 0.7x magnification in FX format shooting. That said, the viewfinder on the newer model is said to be brighter and show more accurate color thanks to an improved coating on its glass pentaprism. It also benefits from a new clearer OLED display element for displaying shooting information.
It appears that 3.2-inch VGA monitors are the order of the day on these Nikon cameras. That said, the D810 is RGBW and has 1,229k dots compared to the 921k dots of the D800/E. This should make it easier to see in bright daylight and give it better color reproduction. Its color balance and brightness can also be customized, which should mean no more complaints about "greenish" screens.
It's no secret that the big files from the D800/E can be a handful for some photographers and their hard drives, especially if they always shoot RAW. Therefore, the option of RAW Small files in the D810, which produces smaller files which are quicker to deal with, could be a big bonus for some photographers.
With the D800/E or D810 there's the option to shoot to one SD memory card and one CompactFlash card. The dual card slots can be used for instant backup, overflow, or to shoot combinations like video to one and stills to the other.
Both generations of camera use Nikon's F-mount, meaning there are plenty of lens options out there.
The D810 will launch at the same US$3,300 price that the D800E was when it was released, which has it ringing up for $300 more than the D800. However, you can expect the older duo to come down in price by a couple of hundred dollars once the new camera hits shelves.
It's clear to see that the new Nikon D810 is a significant, though not a revolutionary, upgrade to the D800/E. Does that make it worth the extra cost compared to one of the older models? Well, that's going to depend on whether improved features like a higher frame rate, wider ISO range and the addition of RAW Small files will make a difference to you. It's the same conundrum when questioning whether to upgrade from a D800/E to the new model.
If you're looking for a DSLR to primarily use for video, then the D810 looks to be a much better option. And if you shoot events, the RAW Small files from the D810 could make all the difference – as might the wider ISO range for other photographers.
The D810's new split-screen display zoom, which displays enlarged views of two separate areas of the frame side-by-side, could swing it for photographers who specialize in landscapes or architecture. Then there's the redesigned mirror sequencer / balancer unit, which minimizes vibration during shooting. The electronic front-curtain shutter could do the same for those who shoot slow-shutter landscapes or astrophotography.
It's also worth remembering that a comparison of core specifications like this one is never going to be exhaustive, and that some improvements or differences that we didn't cover might be just as important to you. For example, you might find that the slightly narrower and deeper grip of the D810 makes it feel considerably different in your hands. As such we'd always advise getting some hands-on time with a potential new camera before making that all-important purchase.