Canon EOS 10D EOS 10D INSTRUCTIONS - Page 71

When Autofocus Fails (Manual Focusing) Autofocus can fail to achieve focus (the focus confirmation light blinks) with certain subjects such as the following: (a) Low-contrast subjects (blue sky, solid-color walls, etc.). (b) Subjects in low light. (c) Extremely backlit reflective subjects (car with a reflective body, etc.). (d) Overlapping near and far objects (animal in a cage, etc.). In such cases, do one of the following: 1. Focus an object at the same distance as the subject and lock the focus before recomposing. 2. Set the lens focus mode switch to < MF> (or < M> on older lenses) and focus manually. (→p.27) Manual Focusing 4 1 Set the lens focus mode switch to (or on older lenses). 2 Focus by turning the lens focusing ring until the subject is in focus in the viewfinder. Focusing • If you press the shutter button halfway during manual focusing, the active AF point and the focus confirmation light in the viewfinder will light when focus is achieved. • If focus cannot be achieved with an external Speedlite's AF-assist beam, select the center AF point. An off-center AF point may not be able to achieve focus. • With USM (Ultrasonic Motor) lenses (except those not having a distance scale), you can use the focusing ring to fine focus after focus is achieved in the One-Shot AF mode (full-time manual focusing). 71