Canon Rebel SL 1 EOS 100D Instruction Manual page 80

Using AF to Focus (AF Method)
_ Focus the subject.
_ Aim the AF point over the subject and
press the shutter button halfway.
_y,, W hen focus is achieved, the AF point
will turn green and the beeper will
sound.
_y,, I f focus is not achieved, the area
frame will turn orange.
Take the picture.
_ Check the focus and exposure, then
press the shutter button completely to
take the picture (p.74).
Q
80
When the camera does not focus the desired target subject with
automatic AF point selection, switch the AF method to zone selection or
[FlexiZone - Single], and refocus.
Depending on the [Ir_: Aspect ratio] setting, the number of AF points
wil! differ. At [3:2], there will be 31 AF points. At [1:1] and [4:3]. there will
be 25 AF points. And at [16:9], 21 AF points. Also, at [16:9], there will be
only three zones.
For movie snooting, there will be 21 AF points (or 25 AF points if
[640×480] is set) and three zones (or 9 zones if [640x480] is set).