Chapter Nine: The Autofocus Menu
Heretofore, configuration options for autofocus were scattered across several other menu items, but with the significant improvements in autofocus, and the number of options to manage them, it was (wisely) decided that autofocus should have its own tab in the camera’s menu structure.
In this chapter, the initialism AF is used widely to represent “autofocus,” consistent with the use of the term in the Canon Instruction Manual.
AF1: AF Config. Tool
The AF1 menu may be the most complex menu the camera has to offer. Fortunately, once you’ve set its parameters to reflect your own personal preferences, there is generally little or no need to revisit this menu. In fact, many users never find it necessary to fine-tune this menu.
This menu applies only when AF mode is set to AI Servo (or to AI Focus when AI Focus is working in AI Servo mode). The intent is to broaden your autofocus management capabilities when the subject is mobile.
This menu allows adjustment of three parameters: Tracking Sensitivity, Acceleration/Deceleration Tracking, and AF Point Auto Switching. These three parameters are common to all six of the different AF cases, and different values in each of the parameters determine the characteristics of each case.
In an effort to limit the number of buttons on the camera, Canon gave the RATE button unique responsibilities when the AF1 menu is active. You will find that the great majority of the menus and options in the AF menus provide in-camera help, and are accessed by pressing the INFO. button.
When you enter the AF1 menu, the top-most icon (that of an athletic runner) will be pre-selected. If you want to apply a case other than Case 1, use the Quick Control Dial to navigate up or down the list of case icons on the left margin, watching the case-description text in the box to the right of the icons. Once you’ve selected the desired case, press the RATE button to access the related parameters. Again, use the Quick Control Dial to access the parameter you wish to customize. Next, press the SET button. Now, use the Quick Control Dial to scroll across the value range to select the desired value. Press the SET button. Again, use the Quick Control Dial to navigate to the next case parameter if necessary. Press the RATE button to return to the AF1 menu (be aware that there is no prompt on the LCD monitor to use the RATE button to return to the AF1 menu).
Note that the new value is indicated with a black block arrow, and the default value is indicated with a gray block arrow.
Should you decide that your efforts to fine-tune these parameters has gotten out of hand, simply re-access the list of parameters for each case to be reset and press the erase (garbage-can icon) button; this will reset all three parameters for that case. As an alternative, you can select each parameter individually, and then reset the black block arrow to align with the gray block arrow. Press the RATE button to return to the AF1 menu.
Case (1 through 6)
All six cases are configured using values for Tracking Sensitivity, Acceleration / Deceleration Tracking, and AF Point Automatic Switching. The difference between the cases is the values assigned to each of those autofocus characteristics.
Tracking Sensitivity
Often, while you’re concentrating on tracking a mobile subject, another object enters the viewfinder’s image. Tracking Sensitivity attempts to let you predetermine how you want the autofocusing system to behave when that occurs. If you want the camera to ignore such an intrusion, set the scale to the minus side. However, if you want it to move the focus to the new subject, essentially ignoring the old subject, set the scale to the plus side.
As shown along the right edge here, there is a reasonable amount of text available in the in-camera Help to remind you of how this function operates. Remember, you must continue to hold down the INFO. button as you scroll with the Quick Control Dial.
Accel./Decel. Tracking
There are two general classes of mobile subjects: those that are on a single course and moving at a consistent speed, and the subjects that erratically change speed or do not maintain a single course. For smoothly moving subjects, such as a gliding heron or egret, set this value to 0. However, if you’re trying to photograph a fox chasing a rabbit or if your subject is a basketball player in motion, then set the value to 1 or 2, depending on the degree of randomness in speed or direction.
AF Pt Auto Switching
The settings for this option apply only when you have set AF Point Selection to 61-Point Auto Selection AF, Zone AF, or AF Point Expansion.
In each of those three modes, there are a number of responsive focus points. The active focus point will move to another responsive focus point as the camera attempts to follow the subject moving across the framed image. A setting of 0 lets the camera attempt to maintain a balance of AF stability with tracking, while a non-zero value causes the camera to switch the focus point more quickly; the higher the value, the faster the switch.
AF2: AI Servo
The AF2 menu gives you control over focusing techniques while you’re using continuous shooting. As its name implies, the AI Servo 1st Image Priority option applies to the first exposure in a continuous shooting situation. The AI Servo 2nd Image Priority option is a bit of a misnomer as the setting for this option applies to the second exposure and all subsequent exposures taken while the shutter button is held down.
AI Servo 1st Image Priority
This option offers three choices. Equal Priority attempts to ensure a balance between release timing and achieving focus. Release Priority allows the shutter to operate even if the camera is not focused. Focus Priority requires that focus be achieved before the shutter is released; with a subject that is flitting across the viewfinder, you may never achieve focus if you’re using something like Spot AF on the AF Point Selection list.
AI Servo 2nd Image Priority
With this option, you can specify the priority to give to the second and subsequent exposures when using continuous shooting. Equal Priority and Focus Priority function here just as they do in the 1st Image Priority setting, but the Release Priority has been replaced with a Shooting Speed Priority setting to accommodate the needs of continuous shooting. When you select Shooting Speed Priority, the camera will maintain the speed of continuous shooting, regardless of focus.
If I were trying to capture a sequence of photos that clearly identified a racer as that racer was breathlessly approaching the finish line, and I needed a shot of the racer crossing the finish line, then I would probably set up AI Servo 1st Image Priority to use Focus Priority. It would give me a sharp photo of the racer, regardless of his immediate place on the course, and I would set the AI Servo 2nd Image Priority to use Shooting Speed Priority to ensure that somewhere in that string of continuously shot pictures, there would be one showing the racer crossing the finish line, regardless of just how sharp the image will be.
AF3: One Shot
USM Lens Electronic MF
Some high-end Canon lenses, such as the EF 85mm f/1.2L II USM, have an electronic focusing ring for use in manually fine-tuning focusing.
This option applies only while AF mode is set to One-Shot. With the Enable After One-Shot AF choice selected, you press the shutter button halfway to let the One-Shot function achieve focus, but then—while continuing to hold the shutter button halfway down—use the electronic focusing ring to make any minor adjustments. To ensure that you do not inadvertently change the focus on subsequent photos, select Disable After One-Shot AF. If you select Disable In AF Mode, then the electronic manual focusing ring will be functional only when the AF/MF switch on the lens is set to MF.
AF-Assist Beam Firing
Most Canon Speedlites have the ability to generate a brief series of low-power flashes that can be used to assist the camera in focusing. By default, the Enable choice is set. However, there are times and places in which this burst of light would be inappropriate. When you choose the Disable setting, for example. There are some Speedlites that also have an infrared (IR) beam that can be used for AF assist. When the IR AF Assist Beam Only setting is selected, there will be no visible-light flashes for AF assist.
One-Shot AF Release Prior
There are only two settings available with this option. If you choose Release Priority, then when the shutter button is pressed, the shutter is released even if the image isn’t quite in focus. This is what you would expect a photojournalist in a war zone to use. Conversely, the Focus Priority setting ensures sharp focus has been attained before the camera will allow the shutter to be released; it would be the usual choice for a wedding or portrait photographer.
AF4
Lens Drive When AF Impossible
Not often, but frequently enough to be a real bother, you may focus on an object that the AF system just cannot resolve. This can happen when you’re shooting a bamboo forest, a box of soda straws, or anything that has no significant horizontal lines, and you have chosen a focus point that is not sensitive to vertical lines. In that case, it’s easy to simply move the focus point to use one of the cross-type focus sensors. (See the next option on this menu, Selectable AF Point.) But if you have the focus point on a subject that has a smooth, uniform texture and color without sufficient detail or contrast for the AF system to work with, or if you’re simply too close for the lens that is currently mounted, the typical result is that the lens oscillates between its focusing limits, trying to find an object on which to focus.
This option has two settings. With the Continue Focus Search setting, the lens will continue trying to find focus; that’s good if the problem is one that you can resolve by changing the focus point. However, if you know the AF system is not going to be able to find focus, select the Stop Focus Search setting and use manual focus. Very long telephoto lenses can spend an inordinate amount of time attempting to achieve focus, so the Stop Focus Search is commonly set when using one in that class of lenses.
Selectable AF Point
The Selectable AF Point option allows you to trade off precision for speed. Certainly, the more points available for focusing, the more precise that focusing will be. When I’m down on my kneepads trying to focus on the anthers of a blossom that’s positioned just as I want it in the viewfinder or in Live View, speed is not a consideration. However, just a few degrees of displacement in order to put a focus point just where I need it may ruin the composition (actually, I try to use manual focus for most of those pictures). Selecting the 61 Points setting to have access to as many as 61 different focus points in the frame is helpful. Be aware that some small-aperture lenses will not be able to utilize all 61 points.
At the other extreme, having to navigate across as many as 11 horizontal spots to identify the focus point to be used can interfere with the opportunity for composition in time-sensitive situations. Activating fewer potential focus spots can be a real advantage, as long as those spots cover the probable field for the particular photograph. The 9 Points setting is the extreme setting in this regard, with the 15 Points setting enlarging the field a bit horizontally. If you look carefully, you will notice that these focus points are arranged as rectangles, not as the diamonds that you may have encountered in other cameras.
The Only Cross-Type AF Points setting provides 41 focus points, which is what remains after the non-cross-type AF points are removed from the full 61-point field. The use of this type of field eliminates the problem of focus searching when you’re attempting to shoot an image that has strong vertical components. Though this selection may prevent the selection of a non-cross-type focus point, those points will still be used in assisting focus, such as in focus tracking. Here again, be aware that some small-aperture lenses will not be able to utilize all 41 points.
Select AF Area Selec. Mode
When you press the AF point selection button, you get a display of all the modes available. By default, all of those modes are active (they are displayed in bright white outline) and any one can be selected to be the current mode. However, if you determine that there are simply too many being displayed as active, or there are some that just don’t relate to the kind of photography you’re involved in, this is the menu option that allows you to determine which settings to deactivate (the setting is not removed from the AF Point Selection display, but is significantly dimmed).
Once you have selected the Select AF Area Selec. Mode option, press the SET button. Use the Quick Control Dial or the Multi-controller joystick to select a mode to be deactivated, and press the SET button. Repeat for any other modes that are to be deactivated. You will see the check mark above the icon for each mode disappear as that mode is deactivated (note that you cannot deactivate the one-point AF mode). When all mode activation and deactivation is complete, you must select the OK setting prior to pressing the SET button.
AF Area Selection Method
Selecting an AF area is a two-step process. The first step is to press the AF point selection button (
), which will display the AF area configurations (or modes) available. The second step is to select which of these modes is to be used. By default, the M-Fn button is the active control for that second step: you repeatedly press the M-Fn button until it selects the mode you wish to use. Some users find that an awkward reach. Canon has responded by making the Main Dial an available alternative. This option allows you to select which control is to be used.
Orientation Linked AF Point
The Orientation Linked AF Point option is an interesting feature; I’m still trying to decide whether I’ll bother with using it, but for some it could be a nice extension to the AF capabilities of the camera. As it comes from the factory, this option is set to Same For Both Vert/Horiz, which is what most of us have used for a considerable time. But some photographers, such as wildlife photographers, find that while the majority of their photos are shot in landscape, their best shots are those serendipitous portrait-orientation shots they’re able to capture when they encounter a subject head-on. Too many of those types of shots are lost because the camera requires so many adjustments for the portrait-orientation photo that the subject has long since departed the scene by the time we set the focus mode and select the focus point.
That scenario is precisely the situation the Select Separate AF Points setting is for. Once this setting is established, you can establish an AF area selection mode and an AF point or zone for each of three orientations: normal landscape mode, portrait mode with the grip at the top, and portrait mode with the grip at the bottom. Simply rotating the camera will automatically make the settings for that orientation active. Fortunately, Canon has determined that the body must rotate about 50 degrees before the change occurs, eliminating false starts caused by an overly sensitive a rotation sensor.
AF5
Manual AF Pt. Selec. Pattern
The Manual AF Pt. Selec. Pattern settings affect the behavior of the focus point as you scroll it across the focus pattern. Using the 61-point display as a reference, if you are trying to scroll the focus point to the left, but encounter the edge of that displayed field, what do you want the camera to do? If you want the focus point to stop at the edge, then select Stops At AF Area Edges. However, if you would like the focus point to “wrap around” and reenter the displayed field at the opposite edge, select Continuous.
AF Point Display During Focus
The AF Point Display During Focus option lets you choose whether the focus point and the currently defined field or zone should be displayed, and when. The first setting, Selected (Constant), always displays the current AF Point Selection field and the current selection point. The All (Constant) setting constantly displays the entire 61 point field and the current focus point. The Selected (Pre-AF, Focused) setting displays the selected focus point whenever the camera is ready to shoot, when selecting an AF point or zone, and when focus is achieved (except in AI Servo mode). The Selected (Focused) setting displays the selected focus point when you’re selecting an AF point or zone, and when focus is achieved (except in AI Servo mode). The Disable Display setting is intended to suppress the display of AF points when you’re not selecting an AF point or zone.
VF Display Illumination
The VF referred to here is the viewfinder, and the purpose of this option is to allow you to specify what kind of illumination of AF points (and the grid, if active) you would like during the autofocus process. The Auto setting automatically illuminates the AF points, the grid, or both when you’re working in low light, while the Enable setting illuminates the AF point, the grid, or both, regardless of light level. The Disable setting terminates this illumination feature. Note that the AF points will still be illuminated when the AF Point Selection button is pressed, regardless of any settings on this option.
AF Microadjustment
Though manufacturing tolerances are extremely tight for Canon DSLRs and their lenses, there is still the possibility of something that will keep a camera or lens from meeting specifications precisely. If you have any concerns about the ability of your camera or lens to achieve sharp focus when the AF system indicates good focus, then give some consideration to this option. You will need to capture several images and study them closely in order to determine whether the camera is focusing in front of the intended subject or behind it. Then you can expand your tests to include another lens or two. If you’re getting essentially the same results with all of the lenses, then your problem is likely in the camera and not in the lenses. That’s when you’ll want to use the All By Same Amount option (figure 9-1): you make one set of adjustments, and they are applied to any and all lenses as they are mounted. However, if the results of the multiple-lens testing are significantly different for each lens, then the problem is most likely with those lenses that focus in front of or behind the subject. If the lens is the problem, you can select Adjust By Lens and create corrections for individual lenses (figure 9-20). As many as 40 lenses may be registered in the camera, along with the adjustment data for each.
