Canon EOS 30D EOS 30D Instruction Manual - Page 78

S Selecting the AF PointN Selecting with the Dial Press the button, then turn the dial or dial to select the AF point in the looping sequence shown on the left. When looking at the LCD panel to select the AF point, note the following: Automatic selection , center , right , top If focus cannot be achieved with an EOS-dedicated, external Speedlite's AF-assist beam, select the center AF point. About AF-Assist beam with the Built-in Flash Under low-light conditions, when you press the shutter button halfway, the built-in flash fires a brief burst of flashes. It illuminates the subject to enable easier autofocusing. In the modes, the AF-assist beam does not light. The built-in flash's AF-assist beam is effective up to about 4 meters/13.2 feet. In the Creative Zone modes when you pop-up the built-in flash with the button, the AF-assist beam will be fired when necessary. Lens' Maximum Aperture and AF Sensitivity The EOS 30D's AF sensor has nine AF points. The center AF point is a high-precision, cross-type sensor sensitive to both vertical and horizontal lines of the subject. The top and bottom AF points are vertical line-sensitive, and the remaining six AF points are horizontal linesensitive AF points. With f/2.8 and faster lenses,* the vertical line-sensitive sensor at the center AF point will also function to attain high-precision focusing. * Except with the EF28-80mm f/2.8-4L USM and EF50mm f/2.5 Compact Macro lenses. 78