At last, it appears Canon has raised its game, in response to Nikon, and introducing a new breed of camera, the EOS 7D. We put it to the test...
The EOS 7D has a new 19-point AF system. All the points are of the biaxial type and effective with lenses with a maximum aperture of f/5.6 or greater. For extra precision, a second, diagonal (‘X’) f/2.8 or faster cross is located at the central point.
In addition, there are two offset horizontal lines in the middle top, bottom and central points for greater precision. As usual, there are three AF modes: One-shot (for stationary subjects), AI Servo (for moving subjects) and AI Focus, which switches automatically between One-shot and AI Servo when the subject starts or stops moving.
In its default setting there are three methods of selecting the AF point: Single-point AF, Zone AF and Auto-select 19-point AF. The first option allows the photographer to select the AF point, while the last completely hands control over to the camera.
With the Zone AF option, the 19 AF points are divided into five zones and the photographer selects the group of points to use to achieve focus. It is useful with moving subjects when they are tricky to follow with a single AF point, but it tends to target the nearest object in the zone.
It is also harder to keep the focus on a specific part of the scene – the head of a particular player in a football match, for example – than it is with the single-point AF, but at least it helps keep the focus on that player.
The Auto-select 19-point AF setting is a good choice with subjects that move very erratically, but again it tends to look for the closest potential subject. When AI Servo focus mode is in use, however, the photographer can select the starting AF point and the camera tracks it.
Reassuringly, with these modes selected, the active AF point(s) illuminate when Custom Function III-10 is enabled, so it is fairly easy to see whether the camera is tracking the correct subject or not, as with the Nikon 3D tracking system.
Two further AF point selection modes can be added to the default list via Custom Function III-6. These are Spot AF, which is the same as single-point AF but the points are smaller for greater precision, and AF point expansion. In the latter mode the photographer selects the AF point manually, but the EOS 7D may also use the surrounding AF points to achieve focus. I found this very useful when shooting a rugby match. Unlike the Auto-select 19-point AF option in AI Servo mode, though, the surrounding AF points do not illuminate when they are active.
Two options in the custom menu, AI Servo tracking sensitivity (C.Fn III-1) and AI Servo AF tracking method (C.Fn III-3), add a little extra flexibility and complication to focusing on moving subjects. These options have previously only been seen in the EOS-1D Mark III and EOS-1Ds Mark III, and they determine whether the EOS 7D should continue focusing on the subject when a closer object comes into the frame and, if not, how quickly it should respond.
The aim is to help photographers track their desired subject and, where necessary, ignore the sudden appearance of a post or pillar (for example) in the frame when panning. I am impressed with the EOS 7D’s AF system. With subjects that are easy to follow in the viewfinder, I had a success rate in excess of 90%.
In more complicated situations my hit rate dropped because of the increased difficulty of keeping the AF point (or group of points) over the correct subject, but, nevertheless, when the AF point was over the subject I got a sharp result in the vast majority of cases. Provided there aren’t lots of potential subjects milling around the scene, the Auto-select 19-point AF option does an excellent job of tracking the subject in AI Servo mode.
Using the EOS 7D’s wireless flash control, I fired a Speedlite 550 EX flashgun to illuminate these bottles from behind while the built-in flash lit the labels from in front. I found a lighting ratio of 3:1 (external: built-in flash) worked best for this setup.