Canon EOS Digital Rebel XTi EF-S 18-55 Kit User Manual - Page 70

f: Changing the Depth of Field Using the Built-in Flash The flash exposure will be set automatically to match the aperture that was set. The shutter speed will set automatically between 30 sec. - 1/ 200 sec. to suit the scene's brightness. In low light, the main subject is exposed with the automatic flash, and the background is exposed with a slow shutter speed set automatically. Both the subject and background look properly exposed (automatic slow-speed flash sync). If you are handholding the camera, keep it steady to prevent camera shake. Using a tripod is recommended. To prevent slow-speed sync, access the [b Custom Function (C.Fn)] menu's [Flash sync. speed in Av mode] (p.104) and set it to [1/200sec. (fixed)]. Depth-of-Field PreviewN Press the depth-of-field preview button to stop down to the current aperture setting. You can check the depth of field (range of acceptable focus) through the viewfinder. When you want to see the effect of the current depth of field, select the lowest aperture value and while holding down the depth-of-field preview button, look at the viewfinder. Then turn the dial to the right to set a higher aperture value and see how the depth of field changes. 70