This section explains what to do if the focus confirmation light does not light.

In the following cases, the focus confirmation light may not light.

The lens focus mode switch is set to <MF>

If the lens focus mode switch is set to <MF>, the AF mode can be selected, but the autofocus will not operate.

Set the lens focus mode switch to <AF>.

An extender (sold separately) is used

If a separately-sold extender is used together with a lens whose maximum lens aperture value is f/5.6 or higher, the autofocus will not operate.

Check the maximum lens aperture value of your lens. In addition, see the instruction manual of your extender.

Custom function settings are enabled

If [Shutter/AE lock button] is assigned to something other than the default [AF/AE lock] function in the custom function (C-Fn) settings of the camera, the autofocus will not operate and therefore, the focus confirmation light may not light in certain settings even if the shutter button is pressed halfway.

Change the custom function setting by referring to the following list.

Custom Function Setting by Model
Camera Models	Custom Function Number	Custom Function Setting (To cancel the setting, press 0.)
EOS-1Ds Mark III	C.Fn IV -1	3 to 0
EOS-1Ds Mark II	C.Fn -04	1 to 0
EOS-1Ds	C.Fn -04	1 to 0
EOS-1D Mark IV	C.Fn IV -1	3 to 0
EOS-1D Mark III	C.Fn IV -1	3 to 0
EOS-1D Mark II N	C.Fn -04	1 to 0
EOS-1D Mark II	C.Fn -04	1 to 0
EOS-1D	C.Fn -04	1 to 0
EOS 5D Mark II	C.Fn IV-1	3 to 0
EOS 5D	C.Fn -04	1 to 0
EOS 7D	C.Fn IV-1	Check the custom settings. (*)
EOS 60D	C.Fn IV-1	Check the custom settings. (*)
EOS 50D	C.Fn IV-1	3 to 0
EOS 40D	C.Fn IV-1	3 to 0
EOS 30D	C.Fn -04	1 to 0
EOS 20D	C.Fn -04	1 to 0
EOS 10D	C.Fn -04	1 to 0
EOS Kiss X4/EOS REBEL T2i/EOS 550D	C.Fn IV C.Fn-9	1 to 0
EOS Kiss X3/EOS REBEL T1i/EOS 500D	C.Fn IV C.Fn-10	1 to 0
EOS Kiss X2/EOS DIGITAL REBEL XSi/EOS 450D	C.Fn IV C.Fn-10	1 to 0
EOS Kiss F/EOS DIGITAL REBEL XS/EOS 1000D	C.Fn IV C.Fn-9	1 to 0

(*): If the autofocus function is not assigned to the shutter button using the [Custom Controls] function on the Quick Control screen, the autofocus will not operate even if the shutter is pressed halfway, and therefore the focus confirmation light does not light.AF mode is set to One-Shot AF

If focus cannot be achieved, the focus confirmation light < > in the viewfinder will blink. If this occurs, a picture cannot be taken even if the shutter button is pressed completely. Recompose the picture and try to focus again. Or see below.

Difficult subjects for AF (Auto Focus)

AF (Auto Focus) can fail to achieve focus (the focus confirmation light blinks) on certain subjects such as the following:

• Low-contrast subjects. (ex. blue sky, solid-color walls, etc.)
• Subjects in low light.
• Extremely backlit reflective subjects. (ex. car with a reflective body)
• Overlapping near and far objects. (ex. animal in a cage)
• Repetitive patterns. (ex. Skyscraper windows, computer keyboards, etc.)

In such cases, do either of the following:

• Focus on an object at the same distance as the subject and lock the focus before recomposing.
• Set the lens focus mode switch to <MF> and focus by turning the lens focusing ring until the subject looks sharp in the viewfinder.

AF mode is set to AI Servo AF

In Creative Zone modes (except for <A-DEP>), the beeper will not sound even when focus is achieved.

Also, the focus confirmation light < > in the viewfinder will not light.

AF mode is set to AI FOCUS AF

When focus is achieved in the AI Focus AF mode with the Servo mode active, the beeper will sound softly. However, the focus confirmation light < > in the viewfinder will not light.