Buying guide: best top-end SLR

If you want to be a pro, you should be looking at these

Canon s 1DX

DSLRs remain the camera of choice for most semi-pro and pro photographers, even though some are now turning to high-end compact system cameras such as the Olympus OM-D E-M1 or Fujifilm X-T1. Although top-end SLRs are not cheap, they deliver a high level of performance, based around full-frame sensors; they also have a wide range of customisable controls, and support lots of specialist lenses, accessories and studio equipment.

As you'd expect from a camera costing the same as a decent used car, higher-end SLRs have myriad autofocus options, impressive ISO performance and often (but not always) fast continuous shooting. They tend to be built like tanks too, since they have to meet the demands of professional press, sports and adventure photographers, who are often working in demanding, deadline-driven environments. When it comes to choosing a top-end SLR, the biggest decision is whether to go for a full-blown pro model, such as the Nikon D4S, or to save money by opting for a camera that also appeals to advanced enthusiasts and semi pros.

The boundary between these two types of camera often blurs, however. Although you often see well-heeled enthusiasts toting the Nikon D810 or Canon EOS 5D Mark III, they are also widely used by fully paid-up professionals. Read on for more buying advice...

Canon EOS 5D Mark III

Sensor size: Full frame Pixel count: 22.3Mp Screen type: 3.2-inch fixed LCD, 1,040,000 dots Maximum continuous shooting rate: 6fps Maximum video resolution: 1080p

Read our full Canon 5D Mark III review

This is a perfect example of a pro-spec SLR that also appeals to serious amateurs. While the 5D Mark III is a very powerful camera, it wears its power relatively lightly, and weighs nearly 400g less than the 1DX. At the heart of the 5D Mark III is a high resolution 22.3Mp sensor, and while this is outgunned by the 36.3Mp resolution of arch-rival the Nikon D810, it still delivers masses of detail – and the smaller raw files don't take up so much card space or computing power.

Canon EOS 5D mk III

The 5D Mark III has a faster burst rate (6fps) than the D810, too, so this an impressive performance for a full-frame camera. While the 5D Mark III weighs less than the 1DX, it has the same autofocus system. The camera offers no less than 61 AF points, of which 41 are cross-type sensors and five are dual cross-type (its predecessor only had a nine-point AF system). Noise is very well controlled through the ISO range and a dual card slot adds to the camera's practicality. Unlike the D810, there is no pop-up flash, however. It's also a shame that the rear screen is fixed, but these are minor drawbacks on an otherwise excellent camera.

Nikon D810

Sensor size: Full frame Pixel count: 36.3Mp Screen type: 3-2 inch fixed LCD, 1,229,000 dots Maximum continuous shooting rate: 5fps Maximum video resolution: 1080p

• Read our full Nikon D810 review

The Nikon D800's 36.3Mp sensor caused a big stir when it was released in 2012, offering the highest resolution of any Nikon SLR to date. While this enables superbly detailed images, you'll need to make sure your focussing skills (and lenses) can keep up, as any lack of sharpness is painfully obvious.

Nikon D810

Nikon has since replaced the D800 with the D810, which keeps the same resolution but removes the anti-aliasing effect from the filter in front of the sensor (the earlier D800E offered a reduction in anti-aliasing rather than full removal).

The D810 brings a number of improvements over the D800, including a higher resolution display, faster continuous shooting (5fps vs 4fps), 33% longer battery life and Picture Control 2.0 image effects, which now include a Clarity micro-contrast adjustment and a Flat mode for maximum dynamic range – especially useful for video.