Canon EOS 5D Mark III review

Canon has pulled out every proverbial stop for the EOS 5D Mark III. The sensor is new and was designed specifically for this model. It's got more auto-focus points, an improved movie mode and it's faster and more responsive all round.

Following the three-and-a-half-year-old Mark II, it represents a logical next step. The question is whether the specs are sufficiently improved to tempt an upgrade from existing Mark II users.

It can be bought for £3,000 for the body only.

The Mark III upgrades

The 5D's new sensor remains a 36x24mm chip, which matches a regular frame of 35mm film, but the number of effective pixels has been marginally increased, from 21.1 to 22.3 million.

The 5D Mark III's sensor is brand new. It's a full-frame element with 22.3 million pixels -- slightly more than its predecessor.

More importantly, the processor has been upgraded from Digic 4+ to Digic 5, which Canon claims is 17 times faster than the previous generation. This means the camera can more effectively analyse the composition of the image and quickly choose the most appropriate settings. It also allows for better image noise reduction, allowing you to shoot at higher sensitivities without introducing excessive noise into your pictures.

Canon's own tests suggest that images shots at ISO 6,400 on the Mark III match those shot on other cameras at just ISO 1,600.

The auto-focus system has been significantly upgraded, with the Mark II's nine AF points expanded to a far more versatile 61. Exposure compensation is broader (+/-5EV, as opposed to the Mark II's +/-2EV). And maximum sensitivity in regular use is ISO 25,600, expandable to ISO 102,400 -- up from the previous best of ISO 6,400.

It has a larger monitor (3.2 inches versus 3 inches), better eyepiece coverage (100 per cent versus 98 per cent), and a wider choice of display overlays. In almost every sense, the Mark III is a significantly better camera than its predecessor. There should be more than enough here to tempt an upgrade from the Mark II's existing user base.

Around the back, the EOS 5D Mark III's display is larger than average, stretching to 3.2 inches.

Handling

Like the Nikon D800, it has dual memory card slots to take CF and SD formats. You can optionally write different image formats to each one, to keep your raw and JPEG shots separate. I used a Class 10 SD card in my tests and achieved manual shot-to-shot times of less than a second. Burst mode tops out at six frames per second (another upgrade on the Mark II's 3.9fps).

At this rate the buffer was filled after 14 shots when shooting raw and six when snapping raw and JPEG combined. A slower secondary burst mode pushed this to 17 raw shots (eight raw and JPEG combined), before it had to pause to offload some data onto the card.

Canon's literature claims that it's possible to capture 18 raw files in a single burst when using UDMA 7 CF cards.

The 5D Mark III has dual memory card slots to handle both CF and SD media. You can write separate formats to different cards.

Exposure compensation stretches to +/-5EV in 1/3EV steps, the control for which is neatly paired with exposure bracketing, with the rear quick-control dial adjusting the setting on the regular scale and the top-mounted main dial used to extend this by a further three stops in each direction.

It's hard to fault the build quality. The buttons have a soft but sure travel, the control wheel is damped so that it doesn't click excessively and the body is weather-hardened magnesium alloy. Even with a chunky 24-105mm lens fixed to the front, it's well balanced and comfortable to hold for extended shoots. Indeed, it was so well balanced that I could even hand-hold quarter-second exposures without any lateral blur.

This hand-held quarter-second exposure shows no sign of lateral movement from the camera body, resulting in sharp surroundings and an attractive blurred weir (click image to enlarge).

Stills tests

I tested the 5D under very mixed conditions, with both direct sunlight and overcast skies, using 16-32mm and 35-105mm lenses. In all situations the chosen lens was quick to find focus, and to refocus following recomposition.

Tones were extremely realistic and true to their originals throughout my tests. Even flowers and blossom, which are traditionally tricky for a camera to expose well in direct sunlight, were accurately rendered. The white apple blossom below retains an impressive level of detail, rather than burning out.

Flowers are traditionally difficult to expose in bright sunlight, yet this apple blossom is full of detail (click image to enlarge).

The 22.3-megapixel sensor delivers shots of 5,760x3,840 pixels, which leaves you plenty of opportunity for cropping in to fine detail, even if you don't have a lens that will get you as close as you would like. There's plenty of wasted space around this chicken (below), yet with so many pixels to play with, zooming to 100 per cent reveals individual hairs and eyelashes, allowing for significant cropping for both web and print use.

With so many pixels to play with you can crop right into your images, here revealing this chicken's eyelashes (click image to enlarge).

It does an excellent job of differentiating between very subtle changes in tone, even on washed-out subjects like the white fresco below, where it's easy to make out individual strokes in the paint on the flat surfaces.

Despite the limited palette in this frame, the EOS 5D Mark III has captured plenty of detail, including individual brush strokes (click image to enlarge).

It has a built-in HDR feature, but even without it, the dynamic range of its images is excellent, with subtle detail captured in the darkest parts of the shot. This shop window displays books both along the glass at the front and at the back of the store, where they are shrouded in darkness -- enlarging the shot to 100 per cent reveals how clearly the 5D rendered them.

The dynamic range in this photo means that at full size it's easy to make out the books in the darker back of the shop (click image to enlarge).

Low-light performance is good. I tested it at ISO 6,400 -- the level at which Canon claims it performs in a similar manner to other cameras set to ISO 1,600. Although it naturally introduces a higher degree of noise than would usually be acceptable, the results are still sharp enough to read the labels of food tins from a couple of metres away in the lightest parts of the image. Further from the lens, and from the light source, the detail is lost at an accelerated rate but the results remain usable.

This frame was shot at ISO 6,400, and although there's a higher degree of noise than I'd like, it's still easy to make out fine detail in the better-lit portions, such as the writing on tin labels (click image to enlarge).

Video test

The EOS 5D Mark III's video performance is very impressive, and its soundtracks have to be heard to be believed. I left the recording level set to manual throughout my tests and the 5D picked up everything, from surrounding birdsong to the rustle of my coat and even my footsteps.

If this is too much for your needs, you can manually control it on a 64-point scale or switch off sound recording altogether. There's also a wind noise reduction option.

There's a dedicated silent control setting for shooting movies that lets you tap the four compass points of the rear control wheel to make adjustments without clicking buttons, so your actions don't affect the soundtrack. Needless to say though, if they change the lens aperture, then you'll still induce small clicks.

Native movie formats are 1,920x1,080 pixels at 30 frames per second, 25fps or 24fps, 1,280x720 pixels at 60fps or 50fps, and 640x480 pixels, again at 60fps or 50fps. Picture quality was excellent throughout my video tests, with foliage and fast-flowing water very clearly captured. There's no powered zoom, of course, and there was no evidence on the soundtrack of noise caused by manual zoom adjustments.

Compensation for changing light levels was swift and smooth, and enabling the lens-based image stabilisation was very effective in smoothing out mobile handheld shots.

Conclusion

These results really do speak for themselves. The 5D Mark III consistently captured sharp, well-exposed shots throughout my tests. The auto-focus subsystem was sharp, and with 61 points, it was easy to get exactly the shot I was after.

The EOS 5D Mark III represents a significant improvement on the specs of the 5D Mark II -- and it's probably enough of an advance for even Mark II users to justify trading in their existing kit.

When compared directly with the D800, Nikon might just have the edge in terms of hardware layout, but where it really matters -- the quality of the output -- there's nothing between them.

If you've already bought into the Canon platform, there's no reason to be switching allegiances. But on this evidence, it would seem there's every reason to consider an upgrade if your existing EOS is starting to feel a little old.