Canon EOS 5D Mark III Review

Ultimately, it is the image quality that makes a camera worth buying. For a digital SLR, image quality greatly depends on the lens used. While color, noise, contrast and exposure are properties of the camera, distortion, vignetting and chromatic aberrations are properties of the lens. Sharpness depends on the weakest link. So, the camera cannot capture more details than the lens lets through. Conversely, a lens can transmit even more details than the sensor can capture.

Image Quality

The 22 megapixels of the full-frame CMOS sensor used on the Canon EOS 5D Mark III give it one of the biggest pixels of any current DSLR. An an 1.6X crop APS-C sensor, it would only give 8.5 megapixels. Such large pixels are ideal for low-night and good dynamic-range, which are the hallmark - along with shallow depth-of-field - of full-frame digital SLRs.

The output quality of t he 5D Mark III, when paired with a high-quality lens, is simply excellent. Image noise levels are nonexistent until ISO 1600 where they are barely visible at 100% view. Even ISO 3200 is nearly perfect and can be used for large prints without concern. ISO 6400 and 12800 certainly show more noise, however nice mid-size prints, say 12" x 8" are easily possible. ISO 25600 and 51200 exhibit high-levels of chroma noise that produce recognizable subjects in a mid-size print but relatively clean 4" x 6" prints. The astronomic ISO 102400 shows yet more noise and is better left for emergencies.

The 5D Mark III has a 63-zone Evaluative metering system which uses information from most of the frame to select an appropriate exposure. Exposures selected by the 5D are conservative and extremely rarely cause over-exposure. It took over a thousand frames to see one over-exposed. However, under exposure is more common than desired and it does reach 2 stops on occasions. Luckily the dynamic-range of this DSLR is excellent and shadow clipping is not so frequent. For scenes that fall within the dynamic-range of the Canon EOS 5D Mark III, it tends to exposure to the left rather than to the right, as is best with digital sensors.

Dynamic-range of this DSLR is top-notch, letting it handle most scenes without much trouble. There is also a Highlight Tone-Priority option designed to preserve highlight details but it only makes a minor difference in this case since the camera rarely over-exposes. Enabling this though, prevents the use of ISO 50 (L) and 100 which are often necessary in broad daylight to avoid stopping-down the aperture beyond the diffraction limit.

One of the new features of the 5D Mark III is its in-camera HDR function. This is a process developed to capture a wider dynamic-range than can be recording using a single image. The HDR feature automatically captures 3 bracketed exposures with 1, 2 or 3 EV between them and blends them together into a singe JPEG which has been tone-mapped into low-contrast image which fits the standard file-format. Technically, this is actually more like Exposure-Fusion but the HDR term is more popular! Uniquely, the 5D Mark III offers 5 blending styles. Here is what Natural looks like with the bracketed shots below, which are optionally saved by the camera.

Image Parameters

Color-rendition and white-balance are dependent on the camera's internal processing which applies for JPEG images and videos. When shooting RAW files, this is done by the processor later. The 5D Mark III can process its own RAW files in the camera or it can be done by software later. Still, it is recommended to properly select image parameters when shooting RAW to get nice image previews, which actually come from JPEG embedded into the RAW file.

Automatic white-balance of this DSLR is generally good. It adapts well to most lighting situations, producing very accurate results outdoors and only leaving the occasional slight cast indoors. Mixed lighting causes most problems but the 5D Mark III rarely produces blatantly wrong results. Custom white-balance works perfectly though.

This DSLR uses the same image parameters based on Picture Styles as the rest of the Canon lineup. There are 5 color styles, 1 monochrome and 3 custom ones. Each style changes the color rendition but hues are generally quite realistic. The best color accuracy is obtained by the aptly-named Faithful setting. This is an immense improvement over the 7D which could not produce colors resembling reality regardless of settings. Faithful defaults to completely anemic sharpness though, so it is necessary to set it around level 3 to get crisp images with barely perceptible sharpening artifacts.

Autofocus Performance

The Canon 5D Mark III gets its own section on autofocus performance because we had some time to stress it. Starting with single-shot AF, this camera is blazingly fast. Even in low-light, it can lock focus very quickly. Using a double-cross point, it does so in less than ¼s. Remember that depending on the lens, there can be 5 or just one double-cross points. The single-cross points are only a tad slower in very low-light, locking focus in 1/3s or less in most situations. The linear points are also quite fast and sensitive enough under typical conditions.

Continuous AF, called AI Servo by Canon, is excellent. The time to get the first focus lock is just as fast as in single-shot AF while the time to refocus is noticeable shorter for small changes in subject-distance. In auto point-selection mode, seeing how fast it detects which points to focus on and bring them into focus is very impressive. With single-point or a group, an unobstructed subject remains in focus nearly at all times. When shooting continuous bursts at 6 FPS shows that the 5D Mark III has no trouble keeping up.

Tracking autofocus is a complex problem and on the 5D Mark III it is controlled by 3 parameters which have combined presets, as described in the capability page of this review. The point is that the camera uses motion prediction to choose when and where to refocus. To get optimal performance, the most suitable parameters must be chosen, otherwise the camera may predict wrong. This is particularly important for subjects which pass behind obstacles such as poles, trees or people standing by. If a subject is occluded by an object for too long, then the camera refocuses on the object and tracking is lost. To get it back, let go the shutter and refocus on the subject.

With the right parameters, the EOS 5D Mark III tracks motion very well. Constant speed subjects are easily tracked at a full 6 FPS and changes of speed are kept up with rather well. When a subject changes direction, there is higher chance of loosing focus, depending on the distance to the background. The further the subject from the background, the better the tracking.

Operational Speed

Put simply, the EOS 5D Mark III very rarely gets in the way of a photograph. This is an extremely responsive camera which is almost already ready to shoot. Button presses get an instant response and the camera returns to shooting mode instantly with a touch of the shutter-release. The performance of this DSLR is characterized by the following numbers:

• Power On: About 3s for a full cycle, including sensor-cleaning. Otherwise, just over 1s.
• Time-To-First-Shot: 1½s. Quite fast.
• Shutter-lag: Instant with extremely short black-out.
• Continuous Shooting: 6 FPS, just as specified.
• Instant Review: 1s, below average.
• Enter Playback: 1/3s. Good.
• Exit Playback: Instant. Excellent.
• Power Off: About 2s, including sensor-cleaning.

The big variables in performance are the sensor which sometimes goes through a cleaning-cycle at startup and the speed of the memory card. Canon claims 16270 shots in a single burst. Even with a moderately slow card, a burst of 25 shots is easily possible. The RAW buffer-depth is 18 shots which lasts 3s at the top frame-rate. The last measurements is battery-life which stands at 950 according to the CIPA standard.

Without a doubt, the Canon EOS 5D Mark III is an impressive camera which is a refined step in the evolution of Canon DSLRs. It is hard to find anything to fault on this camera. From its excellent image quality to ultra-fast autofocus system and broad capabilities, the 5D Mark III is a professional tool ready to tackle any photographic situation.

The 22 megapixels CMOS sensor shows very good dynamic-range and low noise characteristcs. Up to ISO 3200, the 5D Mark III produces top-notch results that can be used for large prints at full resolution. Even ISO 6400 and 128000 are perfectly suitable for most common print sizes, an impressive acheivement even for a DSLR.

The headline 61-point AF system is likely to steal the show for action and sports photographer. It focuses very fast and manages to track moving subjects very well as they change speed and get interrupted by obstacles. This requires good lenses with a bright maximum aperture in order perform at its full potention. With such lens, the autofocus system combined with excellent high-ISO performance make the Canon EOS 5D Mark III one of the best choices for indoor action.

Handling is also very good and will feel right at home with previous Canon owners. There are some quibbles about some ergonomics but they have a minor effect on the potential of this DSLR. In the end, the Canon EOS 5D Mark III delivers everywhere it counts and brings the 5D series up a notch.