With Live Mode, Af Can Fail To Achieve Focus In The Following Cases... - Canon EOS 450D Instruction Manual

Using AF to Focus*
With Live mode, AF can fail to achieve focus in the following
cases:
® Low-contrast subject such as a blue sky and solid-color surfaces.
® Subjects in low light.
® Stripes and other patterns where there is contrast only in the
horizontal direction.
® Under a light source whose brightness, color, or pattern keeps
changing.
® Night scenes or points of light.
® Under fluorescent lighting or when the image flickers.
® Extremely small subjects.
® Subjects strongly reflecting light.
® When both near and far subjects are covenng the AF points, such as
an animal in a cage.
® Subjects which keep moving within the AF point and cannot keep
still due to camera shake or subject blur.
® A subject approaching or leaving the camera.
® When AF is used for an extremely out-of4ocus subject.
® When shooting a soft-focus image with a soft4ocus lens.
® When using a special effect filter.
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