Manual Control Options
The Canon EOS-1D Mark III offers full manual controls for every exposure and shooting parameter. The controls are flexible and clearly implemented. The Mark III is intended for users who rely on a range of manual controls.
Focus
Auto Focus (8.0)
Users identified a problem with Canon EOS-1D Mark III's autofocus system soon after its introduction. While tracking moving subjects, it sometimes missed focus, typically focusing behind them. One of our colleagues, Rob Galbraith, documented the issue on his website. The problem seems most prevalent in bright sun, in hot weather, and with the white balance preset to daylight. Galbraith illustrated the problem when shooting with long lenses.
Canon has released a firmware upgrade since Galbraith published his images, in part to address the focus problem.
Shooting with a 28-70mm and 70-200mm lens, we tried to reproduce the problem with the Mark III. We chose two types of subjects: ones that were smoothly accelerating in a fixed direction (cars pulling out from a stoplight); and ones in chaotic motion (two dogs playing). We set the camera to Aperture Priority, and set the lens wide open at f/2.8. We shot in High Speed Continuous mode. When we tested before the firmware upgrade came out, we had a day with temperatures of about 85 degrees, and we met all the conditions specified for the problem. With the Mark III set to select the AF site automatically, we were disappointed to see that the in-focus points in the pictures of the dogs were as erratic as the dogs themselves – only rare shots were sharp, and the soft ones didn't demonstrate the problem.
The shots of cars were a different story: even with a fairly short focal length, 70mm, many of our images were focused behind the ideal spot. Some shots were sharp, but not the vast majority we hoped for. Though we don't have quantitative data, we believe we reproduced the problem. We saw the problem again when we shot with a manually-selected AF site.
We did not repeatedly produce the other problem noted, in which the Mark III jumped out of focus while shooting a stationary object.
After running the firmware update, we saw improved performance, though our testing location was cooler – in the mid-70s. With the AF site manually selected, the Mark III performed much more reliably – it was impressive. But was it the firmware, or the change in temperature?
Our standard testing for color, resolution, noise, and dynamic range is controlled and repeatable. We know what the variables are, and we know how well we control for them. We are very confident in their reliability. Our trials of the Canon EOS-1D Mark III's autofocus system are entirely different – many variables changed between each set of images we shot – the speed of the cars, color, contrast, how steadily we tracked the camera, and so on.
We also expect that autofocus performance is affected by the photographer's skill. In user forums, implicit in some of the discussion of the Mark III is the idea that pointing it at the subject and pressing the button should be enough. That's not true. Skilled and experienced sports shooters will get many more sharp images than novices, even with the next generation of autofocus.
Photographers who are seriously considering the Mark III have plenty riding on their images. Most are professional. We suggest they test the Mark III before buying it because we saw a problem with the autofocus, and we saw an improvement, but we can't be sure the problem is truly solved.
We should note the autofocus system specifications: it has 19 cross-type sensors, currently the most in any DSLR. Twenty-six more conventional sensors are set between them. Autofocus can be set to One-Shot or Continuous modes. The system can also be set to bias focus in or out for all lenses or for individual lenses. There is an entire menu dedicated to the autofocus. Everything from the brightness of the selected AF point to the fine-tuning of the system for certain lenses can be done in this menu.
Manual Focus (9.5)
The Canon EOS-1D Mark III's viewfinder has a 0.76x magnification ratio, so objects look about three-fourths as big as they do with the naked eye. In general, that makes manual focus more difficult, even though the viewfinder is bright and contrasty. Canon has worked on focusing screen technology to make focus “snap” more noticeably. The screen works better than others with equally low magnification.
Manual focus through the live preview on the LCD works well at 5x or 10x magnification, even in low light. It's clumsy without a tripod, and at 10x magnification camera movement degrades the image. When there's a reason to focus the Mark III manually, live preview is a more accurate option than the viewfinder.
White Balance (9.25)
The Canon EOS-1D Mark III has white balance presets for Daylight, Shade, Cloudy, Tungsten, Fluorescent, and Flash. It also saves up to five custom white balances, can be set to a Kelvin color temperature from 2,500 to 10,000 degrees, and can set white balance automatically. The Mark III has the same white balance fine-tune feature found on other Canons, which shows an x-y graph. From left to right, the adjustment goes from blue to amber, and up to down it goes from green to magenta. To add both blue and magenta, users can push the four-way controller to get the cursor in the lower left quadrant.
White balance bracketing is possible on the Mark III. Three images can be taken in +/- 3 full-stop increments that bias for blue/amber or magenta/green.
More details about the white balance's performance are available in the Testing/Performance section, but the basic verdict is that the automatic white balance isn't very reliable. The custom setting is much preferred, of course, as even the presets aren't as accurate as they should be.
ISO (9.25)
The Canon EOS-1D Mark III has a standard range of ISO 100 to 3200, with extended settings of 50 and 6400. ISO can be set in 1/3, 1/2, or full-EV increments. The Mark III has two DIGiC image processors, and Canon says the two processors enable both the camera's speed and the noise-reduction capabilities necessary for its uniquely high ISO settings. The Mark III doesn't have an Auto ISO setting, but a custom function will cause the camera to shift ISO when a good exposure is not possible at the manual setting.
Exposure (9.0)
The Canon EOS-1D Mark III allows exposure compensation three stops above or below the meter reading. It can be set in 1/2- or 1/3-EV increments. Compensation works in Aperture-Priority, Shutter-Priority, or Program mode. In Manual mode, the exposure scale shows the difference between the camera setting and the meter reading. Though some cameras offer as much as +/- 5 EV of compensation, the three-stop range is plenty. If the meter is that far off, it's better to shoot in Manual mode, unless shooting a range of images for HDR composites.
The Mark III's bracket feature has the same range as the compensation feature. It can be set to shoot two, three, five, or seven exposures, and can be set to vary aperture or shutter speed, or to use the Program mode algorithm.
Metering (9.75)
The Canon EOS-1D Mark III offers several metering patterns, showing some evolutionary change from earlier Canons. Canon's evaluative system compares readings from 63 zones to come up with a final reading. The system does a good job recognizing backlighting and bright subjects against dark backgrounds, but tends to slightly underexpose backlit shots to keep detail in the bright background.
The Mark III offers two settings that act like spot meters. The Spot setting measures 3.8 percent of the frame, either at the center of the shot, or at the active AF point. For a spot zone, 3.8 percent is relatively big – many are half that size. It's possible to retain up to eight different spot readings at once, and have them all show as small tic marks on the exposure scale. The user can then use the EV compensation control to set the exposure value.
The Limited Area mode measures the central 13.5 percent of the frame. It's a metering pattern in search of a purpose. Canon added a center-weighted pattern, which is sometimes useful for landscapes and scenes with relatively even lighting.
In Live Preview mode, the Mark III uses data from the imaging chip to replicate the 63-zone Evaluative mode. We found the Live Preview mode readings match the conventional ones.
Shutter Speed (9.0)
The Canon EOS-1D Mark III has a vertically traveling mechanical focal-plane shutter that snaps exposures from 1/8000 to 30 seconds, in 1/3-EV increments, and has a bulb setting for longer time exposures. The top LCD shows elapsed time during bulb exposures. Flash sync is 1/60 for studio strobes, 1/250 for most flashes, and 1/300 for the 580 EX II.
Aperture (0.0)
Canon EF lenses use electronic links for communication with camera bodies, including aperture. The Canon EOS-1D Mark III can set aperture in 1/3-EV steps. The Mark III also allows users to set the aperture value for metering with optical systems that don't link to the camera. The minimum aperture can be set to f/1.4-9 and the maximum to f/1.0-64.
