How do the two new full frame DSLRs compare? We put the Nikon D800 and Canon EOS 5D Mark III head to head

Comparing the Nikon D800 to the Canon EOS 5D Mark III is something of an inevitability, as both are similar sizes with extremely similar specifications. There are a fair few significant differences, though, from the sensor resolution through to the speed of the burst mode.

The most obvious difference between the two is the sensor resolution, being that the D800 offers just over 14MP more, at 36.3MP. The physical size of the Canon 22.3MP sensor and the D800’s is the same, as both are approximately 36 x 24mm full frame CMOS sensors. 

Thanks to ten more AF points the Canon EOS 5D Mark III is a slight improvement, especially as it also has 41 cross-type points as opposed to 15 on the D800. As cross-type sensors are more accurate this may be evident in the sharpness of the images produced.

Burst mode is a touch more deceptive, as the Canon’s 6fps is taken at full quality, where as the D800 can match it in a cropped 15MP DX mode. This means the full expanse of the sensor won’t be used, with the DX denoting Nikon’s APS-C sensor measurements of 23.6 x 15.7mm being utilised instead.

The native ISO ratings are again in favour of the Canon, with the D800 expandable to 25,600 which the EOS 5D Mark III can achieve natively. In fact the Canon EOS 5D Mark III can go as high as 102,400 using the expanded range.

The majority of these advantages would certainly indicate that the EOS 5D Mark III is geared more toward sports shooting than the Nikon D800, as the faster burst mode and ability to function in low light via the expanded ISO makes it able to shoot at quicker rates and shutter speeds.

Resolution on the LCD screens is similar, at 920k and 1.04 million dots respectively, and the sizes are identical at 3.2 inch. The two viewfinders are 100% coverage as well, and both models are weather sealed.

In terms of movie recording, and monitoring, both have the capacity to shoot at 1080p in either 24, 25 or 30fps modes with a headphone input. This, coupled with the microphone inputs, means the Nikon D800 and Canon EOS 5D Mark III have the potential to be perfect for independent filmmakers, which was a surprising side-market for the EOS 5D Mark II.

Physically the D800 is weighty, by 50g, and the dimensions elsewhere are almost identical give or take 5mm. With such a raft of similarities, it seems odd that the prices are so far apart. 

At almost £3,000 the Canon EOS 5D Mark III is over £300 more than the Nikon D800. With the specs being almost the same in a number of important areas, and the differences arguably coming down to the type of photography you shoot, it seems strange Canon would price the camera so highly. 

Although the prices are sure to drop when both cameras hit the shelves, the shortfall is unlikely to become smaller for a fair few months. We’ll be doing a full head-to-head review in the near future, so keep checking What Digital Camera for more. 

Key Specifications

Canon EOS 5D Mark III Nikon D800
22.3 Megapixel full-frame sensor 36.3MP FX (full-frame) CMOS sensor
61-point autofocus Multi-CAM3500FX 51-point AF system
Up to 6fps continuous shooting 
 4fps burst mode (5/6fps in 15.4MP DX crop mode)
Native ISO 100-25,600 sensitivity ISO 100-6400 (50-25,600 expanded)
3.2in, 1,040k-dot screen 3.2in, 921k-dot LCD
14-bit DIGIC 5+ processor EXPEED 3 processing engine
Enhanced weather-sealing Weather-sealed magnesium alloy body
100% field of view optical viewfinder
 100% field-of-view, 0.72x magnification optical viewfinder
£2999 RRP £2690 RRP
152 x 116.4 x 76.4mm, 950g 146 x 123 x 81.5 mm, 1kg