Canon 1D Mark IV vs. Nikon D3S – Autofocus Performance [Part 1]

Canon 1D Mark IV vs. Nikon D3s

We all know that the Canon 1D Mark IV and Nikon D3S are geared toward sports photographers.  While the cameras have found their way into many other photography niches, at their core, these cameras are made for shooting sports.  As an action-oriented camera, nothing defines its performance more so than its autofocus speed and accuracy.

When shooting sports, we can forgive images that are a bit noisier in one camera over the other, and we can forgive a camera with lower resolution than its competitor.  What we cannot forgive, however, is out of focus images.  When shooting sports and other action, autofocus performance is a paramount concern.

In this installment of my evaluation of the 1D Mark IV and the D3S, I am conveying my thoughts and the results from shooting live action sports with both cameras.  Over the course of three NCAA basketball games, I captured a few thousand frames between these two cameras in a variety of action sequences.  In doing so, I tried to balance the real world sports shooter’s goal of capturing as many quality shots as possible with the task of evaluating the autofocus performance of each camera by throwing them into as many challenging focusing scenarios as possible.  Additional sports venues included a collegiate track and field event and a pro motorcycle race.

Through several upcoming posts, I will attempt to convey my impressions of the overall, sports-oriented AF performance of each of these cameras – as well as how they stack up against each other.  But first, we need to understand, at least, the basics of what features are available on each camera.

Camera AF Options and Settings

Unlike many other DSLRs on the market today, the 1D Mark IV and D3S have a very powerful AF system that is highly customizable to your specific shooting environment.  As a result, you can shoot yourself in the foot by failing to familiarize yourself with the customization options for autofocus to your particular subject matter.

In this Part 1, we will take a brief look at the Canon 1D Mark IV’s AF system as it relates to sports photography concerns.

Canon 1D Mark IV AF System

The Canon 1D Mark IV has 45 AF points, 39 of which are cross-type AF points compared to 19 cross-type sensors in the 1D Mark III.  The 39 cross-type AF points only function as cross-type sensors when manually selected.  When auto-point selection is enabled, the same 19 sensors as in the 1D Mark III operate as cross-types.

The 39 cross-type AF points provide horizontal AF points only when used with f/2.8 or brighter lenses.   Certain Canon L lenses (or those with teleconverters attached), however, offer access to the horizontal AF sensor on the cross-type points even though they are not f/2.8 lenses, which are as follows:

Of course, it is possible that Canon may release future L-series lenses that could be added to this list, and update the 1D Mark IV firmware if needed.

All 45 AF points provide vertical points at f/5.6 or below.  The center AF point offers a cross-type functionality with f/4 or brighter lenses, and provides a vertical AF point at f/8, which will accommodate those placing a 1.4x teleconverter on f/5.6 lenses.

Perhaps the most important function in the 1D Mark IV’s AF settings for continuous shooting is the AF, tracking, release and drive speed priority.  There are four options available under C.Fn III-3.

0: AF priority / Tracking priority

In this mode, the 1D Mark IV gives priority achieving proper focus prior to the release of the shutter, as well as all subsequent shots.  As a result, the shutter is released once the subject is in focus even if this causes a delay in the shutter release.  The continuous shooting speed of subsequent frames may slow down if the 1D Mark IV cannot maintain autofocus on the subject.

This setting is the default setting on the camera.  And rightly so, because it gives focus a priority over all other concerns.  I expect most 1D Mark IV users will be primarily concerned with this as well.

1: AF priority / Drive speed priority

In this mode, the shutter is released on the first frame once autofocus is achieved.  Subsequent frames will give priority to maintaining a continuous shooting speed.  While the frame rate may slow in difficult conditions, it should still be faster than the default setting at position 0.

2: Release / Drive speed priority

This AF mode is all about speed.  The shutter releases when the shutter button is pressed regardless of autofocus acquisition.  Subsequent frames in continuous shooting are captured just the same as in position 1, described above.

3: Release / Tracking priority

This mode is a combination of positions 2 and 0, with the first frame giving priority to shutter release, and subsequent frames giving priority to AF tracking in continuous shooting mode.

AF Point Expansion

Another useful setting for the 1D Mark IV can be found in C.Fn III-8, which enables you to expand a manually-selected AF point to surrounding AF points.  If activated, the manually-selected AF point receives priority for autofocus detection; however, the surrounding AF points will be used to assist in autofocus acquisition if the manually-selected point does not deliver.

Canon suggests that these expansion points are helpful in situations where it is difficult to keep a single point on a subject, such as erratically moving subjects.  Under C.Fn III-8 in the 1D Mark IV’s Custom Functions, there are four options with regard to AF expansion from which to choose.

0: Disable

1: Left/right AF points

2: Surrounding AF points (Anywhere from 3 to 8 expansion points may be used to assist in AF acquisition.)

3: All 45 points area

These settings should be rather self-explanatory; however, note that the use of mode 3 under C.Fn III-8 requires the center AF point to be used for initial focusing.  Subsequent focus tracking may be shifted throughout the focusing frame as the 1D Mark IV tracks the subject.

AI Servo Tracking Sensitivity

By making adjustments withing C.Fn III-2, the sensitivity of the AI Servo tracking can be altered.  The 1D Mark IV provides five settings that range on between “Slow” and “Fast.”  By default, the 1D Mark IV is set to the middle, or neutral, point between slow and fast.

“Fast” sensitivity allows the 1D Mark IV to switch focus between objects quickly, while “slow” sensitivity ignores objects or backgrounds that enter the AF area briefly while tracking your subject in AI Servo mode.

Spot AF

Spot AF allows you to use a smaller portion of the AF sensor, which in turn allows you to focus on smaller objects at greater distances.  This setting is possible via C.Fn III-6-7 by assigning the function to the AF Stop button on certain Canon telephoto lenses.

AF Point Selection

While the 1D Mark IV features 45-selectable AF points, you don’t have to use that many if you don’t want to.  C.Fn III-10 provides the option to limit the number of manually-selectable AF points.  The default is 45 AF points; however, you can also choose 19 points, 11 points, a group of 9 inner points, or 9 outer points.  This is a rather liberal set of options which should satisfy most users’ preferences.

Orientation Linked AF Points

The new orientation linked AF points option is probably the most convenient new feature on the 1D Mark IV.  When I first used the feature on the Canon 7D, it really sucked me in.  If you aren’t familiar with this feature, it is unlockable via C.Fn III-16-1 and allows you to manually select different active AF points that switch depending on the orientation of the camera.

By activating the orientation linked AF points, simply holding the camera vertically (grip on top), horizontally, or vertically (grip on bottom) activates the AF point of your choosing.  While the sports photography implications for this feature are obvious, portraits are a breeze as well when switching between horizontal and vertical compositions.

Registered AF Points

But what if you don’t switch the camera’s orientation?  Using registered AF points under C.Fn III-11, you can switch between two AF points with a single button while maintaining a single orientation of the camera.  For instance, you can switch between AF points on the left and right side of the frame while maintaining a horizontal composition.  You can even program the 1D Mark IV via C.Fn III-6 to use the AF Stop button on certain Canon telephoto lenses to switch between registered AF points.

Wrapping Up the 1D Mark IV AF System

I have touched on the parts and points of the 1D Mark IV AF system that I felt were important to me.  Obviously, an exhaustive discussion of the complex AF system in the 1D Mark IV could go on for much longer; however, I simply wished to provide an overview of the highlights of the 1D Mark IV before we get into the specific performance issues.

Next in this series, I will provide a brief overview of the Nikon D3S AF System as it relates to sports photography.

The Canon 1D Mark IV and Nikon D3S are available from Photography Bay’s trusted retail partner, B&H Photo, at the following links:

Canon 1D Mark IV at B&H Photo

Nikon D3S at B&H Photo

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