Canon Eos Rebel T6i 750d Instruction Manual

							101
f: Changing the Autofocus Operation K
Suited for still subjects. When you 
press the shutter button halfway, the 
camera will focus only once.
When focus is achieved, the AF point 
that achieved focus will be displayed, 
and the focus indicator < o> in the 
viewfinder will also light up.
 With evaluative metering, the 
exposure setting will be set at the 
same time focus is achieved.
 While you hold down the shutter button halfway, the focus will be 
locked. You can then recompose the shot if desired.
One-Shot AF for Still Subjects
Focus indicator
AF point

If focus cannot be achiev ed, the focus indicator  in the viewfinder 
will blink. If this occurs, the pictur e cannot be taken even if the shutter 
button is pressed completely. Recompose the shot or see “Subjects 
Difficult to Focus on” (p.110) and try to focus again.
 If [z 1: Beep ] is set to [ Disable], the beeper will not sound when focus 
is achieved.
 After achieving focus with One-Shot  AF, you can lock the focus on a 
subject and recompose the shot. This  is called “focus lock”. This is 
convenient when you want to focus  on a peripheral subject not covered 
by the Area AF frame.
 When a lens equipped with electronic manual focusing function is used, 
after achieving focus, you can focus manually by turning the lens 
focusing ring while pressing the shutter button halfway. 
						

							f: Changing the Autofocus Operation K
102
This AF operation is suited for moving subjects when the focusing 
distance keeps changing. While you hold down the shutter button 
halfway, the subject will be focused on continuously.
The exposure is set at the moment the picture is taken.
 When the AF area selection mode is set to 19-point automatic 
selection AF (p.104), the camera fi rst uses the manually-selected AF 
point to focus. During autofocusing, if the subject moves away from 
the manually-selected AF point, focu s tracking continues as long as 
the subject is covered by the Area AF frame.
AI Focus AF switches the AF operation from One-Shot AF to AI 
Servo AF automatically if a still subject starts moving.
 After the subject is focused on in One-Shot AF, if the subject starts 
moving, the camera will detect the movement, change the AF 
operation automatically to AI Servo AF, and start tracking the moving 
subject.
AI Servo AF for Moving Subjects
AI Focus AF for Switching the AF Operation Automatically
With AI Servo AF, the beeper will not sound even when focus is achieved. 
Also, the focus indicator < o> in the viewfinder will not light up.
When focus is achieved with AI Focus  AF with the Servo operation active, 
the beeper will continue beeping softly. However, the focus indicator < o> in 
the viewfinder will not light up. Note that  focus will not be locked in this case. 
						

							103
f: Changing the Autofocus Operation K
By default, the AF points light up in red when focus is achieved in low-
light conditions. In Creative Zone modes, you can set whether to have 
the AF points light up in red when focus is achieved (p.342).
Under low-light conditions, when you press the shutter button halfway, 
the built-in flash may fire a brief burst of flashes. This illuminates the 
subject to help autofocusing.
AF Points Lighting Up in Red
AF-Assist Beam with the Built-in Flash
The AF-assist beam will not be emitted from the built-in flash in the 
following shooting modes: , , < 5>, and < C>.
 The AF-assist beam will not be emitted with AI Servo AF operation.
 The built-in flash makes a sound when firing continuously. This is normal 
and not a malfunction.
The effective range of the AF-assist beam emitted by the built-in flash is 
approx. 4 meters/13.1 feet.
 In Creative Zone modes, when you raise the built-in flash with the < I> 
button (p.166), the AF-assist beam will be emitted when necessary. Note 
that depending on the setting for [ 4: AF-assist beam firing] under [ 54: 
Custom Functions (C.Fn)], AF-assist beam will not be emitted (p.340). 
						

							104
19 AF points are provided for autofocusing. You can select the AF area selection mode and AF point(s) suiting the scene or subject.
You can select one of three AF area selection modes. See the next 
page for the selection procedure.
h: Single-point AF (Manual 
selection)
Select one AF point to focus.
q : Zone AF (Manual selection of 
zone)
The 19 AF points are divided into five 
zones for focusing.
r : 19-point automatic selection 
AF
All the AF points are used to focus.  This 
mode is set automatically in Basic 
Zone modes (except < x>).
S  Selecting the AF Area and AF Point K
AF Area Selection Mode
Area AF frame 
						

							105
S Selecting the AF Area and AF Point K
1Press the  or  button 
(9 ).
Look through the viewfinder and 
press the < S> or < B> button.
2Press the  button.
Each time you press the  
button, the AF area selection mode 
changes.
 The AF area selection mode currently 
set is indicated on the top of the 
viewfinder.
h : Single-point AF 
(Manual selection)
q :Zone AF 
(Manual selection of zone)
r : 19-point automatic selection 
AF
Selecting the AF Area Selection Mode
AF area selection mode
Under [ 54: Custom Functions (C.Fn) ], if you set [5: AF area selection 
method ] to [1: j9Main Dial], you can select the AF area selection mode 
by pressing the < S> or < B> button, then turning the < 6> dial (p.340). 
						

							S Selecting the AF Area and AF Point K
106
You can manually select the AF point or zone. If 19-point automatic 
selection AF + AI Servo AF has been set, you can select any position 
where AI Servo AF is to start.
1Press the  or  button 
(9 ).
The AF points will be displayed in the 
viewfinder.
 In the Zone AF mode, the selected 
zone will be displayed.
2Select an AF point.
You can select an AF point by shifting 
horizontally with the  dial or 
vertically with the < 6> dial while 
holding down the < g> button. If 
you press < 0>, the center AF point 
(or center zone) will be selected.
 In the Zone AF mode, turning the 
 dial will change the zone in a 
looping sequence.
 You can also select an AF point or 
zone by shifting hor izontally with the 
< Y > < Z> keys or vertically with the 
< W > < X> keys.
Selecting the AF Point Manually
 + <
6 >
When you press the < S> or < B> button, the viewfinder displays the 
following:
• 19-point automatic selection AF and Zone AF (manual selection of zone):   M  AF
• 1 pt AF (Manual selection):  SEL N  (Center)/ SEL AF (Off center) 
						

							107
Select one AF point  to be used for focusing.
The 19 AF points are divided into five zones for focusing. All the AF 
points in the selected zone are used for the automatic selection of the 
focusing point(s). It is effective for moving subjects.
However, since it is inclined to focus the nearest subject, focusing a 
specific target is harder than with single-point AF.
The AF point(s) achieving focus is displayed as < S>.
AF Area Selection Modes K
h Single-point AF (Manual Selection)
q Zone AF (Manual Selection of Zone) 
						

							AF Area Selection ModesK
108
All the AF points are used to focus.  This mode is set automatically in 
Basic Zone modes (except < x>). 
With One-Shot AF, pressing the shutter button 
halfway will display the AF point(s) < S> that 
achieved focus. If multiple AF points are displayed, 
it means they all have achieved focus.
With AI Servo AF, the manually-selected (p.106) AF 
point < S> is used first to achieve focus. The AF 
point(s) achieving focus is displayed as < S>.
r 19-point Automatic Selection AF
AF Using Color Tone DetectionConfiguring the following makes it easier to focus on still human subject.
• Set the AF operation to One-Shot AF.
• Set the AF area selection mode to Zone AF (manual selection of zone) or 
19-point automatic selection AF.
• Under [ 54: Custom Functions (C.Fn) ], set [6: Auto AF point selection: 
Color Tracking ] to [0: One-Shot AF only ] (if set to [1: Disable], basically 
the nearest subject will  be focused on) (p.341).
When AI Servo AF mode is set with 19-point automatic selection AF or 
Zone AF, the active AF point < S> will keep switching to track the 
subject. However, under certain shooti ng conditions (such as when the 
subject is small), it may not be able  to track the subject. Also, in low 
temperatures, the tracking response is slower.
 If the camera cannot focus with the EOS-dedicated external Speedlite’s 
AF-assist beam, set the AF area selection mode to Single-point AF 
(manual selection) and select the center AF point to autofocus.
 When the AF point(s) light up, part or all of the viewfinder may light up in 
red. This is a characteristic of  AF point display using liquid crystal.
 In low temperatures, it may sometimes become difficult to see the AF 
point display because of its characteristics using liquid crystal. 
						

							109
AF Area Selection ModesK
Maximum Lens Aperture: f/3.2 - f/5.6
With all AF points, cross-type AF  sensitive to both vertical and 
horizontal lines is possible. Howe ver, with the lenses below, the 
peripheral AF points will detect only  vertical or horizontal lines (no 
cross-type focusing).
Maximum Lens Aperture: f/1.0 - f/2.8
Besides cross-type focusing (verti cal and horizontal lines detected 
simultaneously), the center AF point can also perform high-precision, 
vertical-line sensitive AF.*
The remaining 18 AF points perform cross-type focusing, as with the 
maximum aperture at f/3.2 - f/5.6.
* Except with the EF28-80mm f/2.8-4L USM and EF50mm f/2.5 Compact Macro.
AF Operation and Maximum Lens Apertures
Lenses that Do Not Support Cross-Type Focusing with 
Peripheral AF Points
Cross-type focusing at the < > and < > AF points is not possible with the 
following lenses:
EF35-80mm f/4-5.6, EF35-80mm f/4-5.6 II, EF35-80mm f/4-5.6 III, 
EF35-80mm f/4-5.6 USM, EF35-105mm f/4.5-5.6, EF35-105mm f/4.5-5.6 
USM, EF80-200mm f/4.5-5.6 II, EF80-200mm f/4.5-5.6 USM
 Cross-type focusing
 Vertical line-sensitive focusing
 Horizontal line- sensitive focusing 
						

							110
Autofocus can fail to achieve focus (viewfinder’s focus indicator  
blinks) with certain subjec ts such as the following:
 Very low-contrast subjects
(Example: Blue sky, solid-color walls, etc.)
 Subjects in very low light
 Strongly backlit or reflective subjects
(Example: Car with a highly reflective body, etc.)
 Near and distant subjects framed close to an AF point 
(Example: Animal in a cage, etc.)
 Subjects such as dots of light framed close to an AF point
(Example: Night scenes, etc.)
 Repetitive patterns
(Example: Skyscraper windows, computer keyboards, etc.)
In such cases, do either of the following:
(1) With One-Shot AF, focus on an object at the same distance as 
the subject and lock the focus before recomposing the shot 
(p.69).
(2) Set the lens’s focus mode switch to < MF> and focus manually.
Subjects Difficult to Focus on
Depending on the subject, focus  may be achieved by slightly 
recomposing the shot and performing AF operation again.
 Conditions that make focusing difficult with AF during Live View shooting 
or movie shooting are listed on page 212.