Canon EOS REBEL XS Instruction Manual page 13

Using AF to Focus*
With Live mode, AF can fall 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.
® The AF point covers both a near and faraway subject (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.
® Autofocusing while the subject is way out of focus.
® Soft focus effect is applied with a soft focus lens.
® A special effects filter is used.
106