Difficult subjects for AF (Auto Focus) (EOS M)
13-Sep-2012
8201598000
Solution
AF (Auto Focus) can fail to achieve focus (the focus confirmation light blinks) on certain subjects such as the following:
- Low-contrast subjects such as the blue sky, solid-color flat surfaces or when highlights or shadow details are lost.
- Extremely bright or dark subjects.
- Stripes and other patterns where there is contrast only in the horizontal direction.
- Subjects with repetitive patterns (skyscraper windows, computer keyboards, etc.).
- Fine lines and subject outlines.
- Under a light source whose brightness, color, or pattern keeps changing.
- Night scenes or points of light.
- When the image flickers under fluorescent or LED light sources.
- Extremely small subjects.
- Subjects at the edge of the picture.
- Subjects strongly reflecting light.
- The AF point covers both a near and faraway subject (such as an animal in a cage).
- Subjects that keep moving within the AF point and cannot keep still due to camera shake or subject blur.
- Autofocusing while the subject is very far out of focus.
- Soft focus effect is applied with a soft focus lens.
- A special effect filter is used.
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 (For information on the focus lock, please refer to the following note and the Related information section).
- Set the lens focus mode switch to <MF> and focus manually.
NOTE
With [One-Shot AF], while you press the shutter button halfway to focus a still subject, the focus will be locked. You can then recompose the shot and press the shutter button completely to take the picture. This is called "focus lock". For further information, please refer to the Related Information section. (In the < 
> (Sports) mode, AF mode is set to [Servo AF] automatically.)
> (Sports) mode, AF mode is set to [Servo AF] automatically.)