Custom Functions on the Canon 70D let you specify with fine-grain control how your camera operates. Autofocus custom functions focus on adjustments related your camera’s autofocus settings.
These custom functions are found in the C.Fn II: Autofocus menu in the second-to-last tab in the settings menu of the camera. There are thirteen customizable functions. Let’s cover each of them individually:
- Tracking Sensitivity has a slider that can be adjusted to five levels between more locked on or more responsive during autofocus tracking in AI Servo autofocus mode. Default is 0, a balance between the two. More locked on will more aggressively attempt to keep focus on one subject, whereas more responsive will attempt to keep track of more subjects, making it easier to switch focus between them.
- Acceleration/deceleration tracking is a slider that can be adjusted to aid in autofocus tracking of subjects that accelerate and decelerate differently. For subjects that start and stop movement more suddenly, a positive setting on the slider will make tracking more sensitive, whereas a negative number is better for subjects that start and stop movement more gradually.
- AI Servo 1st image priority lets you adjust priority between shutter and focus during continuous shooting. Adjusting to release priority will make the camera take the first photo even if focus has not been achieved, whereas adjusting to focus priority will cause the camera to wait for focus lock. Default is a balance between the two.
- AI Servo 2nd image priority is similar to 1st image priority, but setting priority for images after the first shot.
- AF-assist beam firing adjusts the quick initial burst of the flash unit that aids in obtaining focus while using flash. There are four options: Enable will use the AF-assist beam whenever necessary, Disable will turn the beam off entirely, External flash only will only use the beam when using an external flash unit, and IR AF assist beam only will use only the infrared AF-assist beam equipped on Canon Speedlite external flash units.
- Lens Drive when AF impossible lets you turn off the default option of the camera continuing to adjust the drive motor when autofocus cannot be achieved normally. Disabling this function can be useful when using a very long telephoto lens that can take a long time to drive it’s entire focal range.
- Select AF area selection mode lets you choose which AF area selections you can make during normal operation. 1-point AF, Zone AF, and Auto selection AF can each be individually toggled on or off.
- AF area selection method lets you adjust how the autofocus area is selected. By default (option 0), you can toggle between the AF area modes by pressing the AF area selection button. Option 1 lets you use the main dial to switch between the area modes after pressing the AF area selection or AF point selection buttons.
- Orientation linked AF point allows the selected autofocus point or area to be automatically adjusted based on the orientation of the camera. For example, when the option is enabled, if a left-most AF point is selected, rotating the camera to shoot in portrait mode will automatically adjust the AF point to the then left-most AF point.
- Manual AF point selection pattern controls whether the selection of the AF point will loop or not. When enabled, moving the selection past the furthest point will select the opposite point on that row or column.
- AF point display during focus adjusts when the AF point is displayed. Option 0 will constantly display the selected AF point, option 1 will constantly display all 19 AF points; option 2 will display the selection AF point during AF point selection, when the camera is ready to shoot, and when focus is achieved; option 3 will display the selected AF point during selection and when focus is achieved; and option 4 will only show when selecting an AF point.
- VF display illumination sets when the AF points and grid seen in the viewfinder will illuminate with red light (as red light is less disruptive in low light conditions). Option 0 sets the viewfinder to illuminate in red only in low-light conditions, option 1 will enable red illumination at all times, and option 2 will disable red illumination entirely.
- AF Microadjustment allows fine-grain adjustment of the focus depth during autofocus. Generally this setting does not need to be adjusted unless your lens’ focal point is misadjusted in one direction or the other. AF Microadjustments can be individually configured for up to 40 lenses.
Check out our Canon 70D Tips & Tricks Roundup for more info!
