Canon EOS 5D Mark III review

Canon’s 5D series cameras have gained legendary status over the last seven years. Their full-frame (35mm film-size) sensors clearly identify them as professional quality cameras, yet at around half the cost of Canon’s flagship 1D range, they’re a tantalising proposition for semi-professional and amateur photographers. Who needs frivolities like holidays or a social life when you could own a full-frame DSLR?

Before we continue, we feel obliged to bring things back down to Earth. The 5D Mark III currently costs a shade under £2,800, but we recommend budgeting the same again for lenses that do it justice. It uses the same EF mount as consumer Canon EOS cameras, but cheaper EF-S lenses are only designed for cropped sensors and will produce an ominous circular frame when attached to the full-frame 5D Mark III.

Canon makes various keenly priced full-frame EF lenses, such as the 50mm f/1.8 (£80) and 28-135mm f/3.5-5.6 (£375), but the pricier L lenses are a better match for the 5DMark III. Canon sent us the 24-105mm f/4L (£930), 100mm f/2.8L Macro (£820) and 50mm f/1.2L (£1,350) for testing, which we got on with very nicely. Total cost including VAT: £5,900. Still, that’s not unreasonable for people who earn a living with their camera, and those of humbler means can build up their lens collection slowly.

Mark II users considering an upgrade might be disappointed by the modest boost to the resolution, which is up by just 1 megapixel – just 144 pixels wider. The 22-megapixel sensor doesn’t have the wow factor of the Nikon D800 with its 36 megapixels, but for us, it’s more than enough. The benefit of this relatively modest resolution, plus the significantly upgraded processor, is that continuous performance has jumped from 3.9fps to 6fps. Cheaper cameras can match or beat this speed but few can maintain it until the card is full. This was only possible when using a CompactFlash rated at 90MB/s, though. Testing with an SDHC card rated at 95MB/s, continuous shooting fell to 2fps after 28 frames. Continuous raw performance lasted for 19 frames before slowing to 2.5fps for CompactFlash, or 0.7fps for SDHC.

The most dramatic upgrade – and for us, the Mark III’s best feature – is the 61-point autofocus sensor. This is the same one that appears in the flagship EOS 1D X, and is a massive improvement over the Mark II’s 9-point system. The Mark III also gains scenario-based autofocus configuration from the 1D X, with options such as “For subjects that accelerate or decelerate quickly”, or “Instantly focus on subjects suddenly entering AF points”. Each one can be customised via three sliders for Tracking sensitivity, Accel/decel tracking and AF point auto switching.

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This auto switching function is similar to the 3D Tracking feature in Nikon SLRs, but in our tests the Mark III couldn’t match the D800 in its reliability to track moving subjects around the frame. It’s not that surprising, as the D800 uses a 91,000-pixel metering sensor to track subjects by colour whereas the Mark III has just 63 metering zones.

With such a complex array of autofocus controls, we were relieved to find that default settings using a single autofocus point performed superbly when presented with moving subjects in continuous mode. Moving the selected point is extremely quick via the mini joystick or a combination of command dial and rear wheel. 21 of the 61 points are cross-type for added sensitivity, and using an f/4 or brighter lens earns a further 20 cross-type points. By f/2.8, you get five that are dual cross type – essentially four autofocus points stacked on top of each other at 45-degree angles. In short, this is a seriously sophisticated autofocus system that should have Mark II users rushing to upgrade.

The controls tread familiar territory for an EOS camera, and anyone who’s used a 5D Mark II, 60D or 7D will be up and running in minutes. There’s a command dial, rear wheel and mini-joystick, while a row of buttons above the passive LCD screen temporarily assign the dial and wheel to a variety of functions including white balance, drive mode and ISO speed. It inherits the 7D’s live view button, which turns into a record/pause button when the accompanying switch is set to video mode. The depth-of-field preview button is now located in a more conventional place between the lens and handgrip.

The button labelled Rate is new. Pressing it while browsing shots on the 3.2in screen applies star ratings from one to five, which are recognised in software such as Adobe Lightroom. It’s also possible to display two images side by side and zoom into them for close inspection, although not by as much as we’d like. The option to match the zoom and position of two photos could be more elegantly implemented, too.

The Auto ISO mode is more configurable than in previous EOS cameras, with the ability to define the minimum and maximum speeds, and also define a minimum shutter speed threshold. It’s not as flexible as the D800’s, though, as the fastest setting of 1/250s isn’t enough to freeze fast motion. There’s an Auto option for this minimum shutter speed control, which adapts to take into account how camera shake is more likely at longer focal lengths. However, there’s no option to shift the Auto threshold to faster or slower sets of values, as on the D800.

The 5D Mark II was the first SLR to record 1080p video. Today it’s a standard feature across the board, but the Mark III comes with some significant upgrades. AVC compression is at bit rates up to 30Mbit/s, but there’s an option to use all I-Frames, whereby each frame is described from scratch rather than using sub-frames that only describe what’s changed since the previous frame. This generates files up to 90Mbit/s but reduces compression artefacts in fast-moving scenes. Thankfully, clips can span multiple 4GB files up to a maximum of 30 minutes. There’s a choice of 24fps, 25fps or 30fps frame rates, but considering the much faster processor, it’s disappointing that there’s no 1080p capture at 50fps or faster for slow-motion effects.

Comparing stills from each camera’s 1080p video output (shot at f/5.6, ISO 200, 1/50s), they all look pixel-sharp but the Canon can’t match the Nikon D800 or Panasonic GH1 in its ability to capture subtle textures in the soft toy – click to enlarge

The Mark II had a choice of automatic or manual exposure control for videos, but the Mark III adds shutter- and aperture-priority control. The ability to fix the shutter speed at 1/50s for consistent motion blur and let the camera expose automatically using the ISO speed is a major breakthrough, and something that the Nikon D800 lacks. It’s also possible to adjust exposure settings using touch-sensitive controls to avoid mechanical clicks spoiling the soundtrack. There’s no resolution to EOS cameras’ terrible autofocus for video, though. Pressing the AF-ON button while recording overrides manual exposure settings and causes the focus motor to dart violently back and forth.

Details in video clips weren’t as sharp as we’d hoped for, either. The D800 coped better with subtle details such as skin textures and foliage – the 5D Mark III’s output resembled lower resolution footage that had been digitally sharpened. However, this may be the result of Canon’s efforts to rid videos of moiré interference, whereby dense patterns result in swirling lines of interference. This has been a bugbear of ours for some time, and it’s a relief to finally find an SLR that doesn’t exhibit it. Audiences probably won’t be too upset by a slight lack of detail, but psychedelic interference can be really distracting. However, neither the 5D Mark III nor the D800 could match our aging Panasonic GH1 for detail in videos, at that doesn’t suffer from moiré either.

There’s less to report regarding the Mark III’s image quality. Colour reproduction at the default JPEG settings was nothing short of stunning. Using the Mark III with the 50mm f/1.2L lens made us whimper with delight, both while shooting and when we got the pictures onto a PC. Details in JPEGs were quite heavily sharpened, but even when we rolled off the Sharpness and Contrast settings, photos still packed plenty of detail. Raw files processed in Lightroom were seriously sharp.

The Nikon D800 can capture sharper details, but we wouldn’t describe the 5D Mark III as lacking in this respect – click to enlarge

Any concerns about the lack of an integrated flash were quickly allayed by this camera’s noise levels. Nothing else we’ve seen comes close. Skin tones at ISO 1600 were smooth and detailed, and only a little mottled at ISO 6400. With careful processing in Lightroom, raw images at ISO 6400 were good enough for publication. Even ISO 25,600 gave passable results, roughly on a par with the Nikon D800 at ISO 6400.

An f/1.2 lens in front of a full-frame sensor gives an incredibly shallow depth of field – click to enlarge

If you’re largely interested in video, we recommend the Panasonic Lumix DMC-GH2. It’s noisier at high ISO speeds and Panasonic’s lens range can’t begin to compete with Canon’s, but it delivers smooth autofocus and sharp details without moiré – a combination that eludes all the SLRs we’ve seen to date. The 5D Mark III is by no means a poor video camera, though. If you’re happy to focus manually or leave it fixed for the duration of shots, it’s extremely capable.

Shaded skin tones are particularly unforgiving for noise problems, but the 5D Mark III still turns in usable results at ISO 12800 – click to enlarge

For photography, the 5D Mark III is an absolute triumph. It’s fast, its controls are comprehensive and efficient and its image quality is truly breathtaking. The superb colours and details are welcome, but it’s the incredibly low noise that sets it apart, allowing action photography without the need for fast telephoto lenses (which cost a fortune) and taking the pressure off balancing ISO and shutter speeds in low light. It’s a brilliant camera, and one that was very hard to give up at the end of our testing.