114f: Changing the Depth of FieldTo obtain a correct flash exposure, the flash output will be setautomatically to match the set aperture (autoflash exposure). Theshutter speed will be set automatically between 1/200 sec. - 30 sec. tosuit the scene’s brightness.In low light, the main subject is exposed with the automatic flash, andthe background is exposed with a slow shutter speed set automatically.Both the subject and background look properly exposed (automaticslow-speed flash sync). If you are handholding the camera, keep itsteady to prevent camera shake. Using a tripod is recommended.To prevent a slow shutter speed, under [z1: Flash control], set[Flash sync. speed in Av mode] to [1/200-1/60 sec. auto] or [1/200sec. (fixed)] (p.219).The aperture opening (diaphragm) changes only at the moment whenthe picture is taken. Otherwise, the aperture remains fully open.Therefore, when you look at the scene through the viewfinder or on theLCD monitor, the depth of field will look narrow.Press the depth-of-field preview buttonto stop down the lens to the currentaperture setting and check the depth offield (range of acceptable focus).D Using the Built-in FlashDepth of Field PreviewNWhile looking at the Live View image (p.146) and holding down the depth-of-field preview button, you can change the aperture and see how the depth offield changes.COPY