28 FLASH PHOTOGRAPHY 28.3 General Flash Photography28.3 General Flash PhotographyWhen using an automatic flash unit other than a Canon Speedlite, first turn theshutter dial to ”~” (1/90 sec) Then turn the aperture ring to the same aperturewhich you have set on the flash. With the shutter dial on ” f ,” other types ofelectronic flash units can be synchronized either through the hot shoe or via the PCsocket on the side of the camera. These allow two separate flash units to be firedsimultaneously. Set the shutter dial according to the information in the table onthe following page.When shooting with a flash bulb or a manual flash unit, calculate the aperture witha guidenumber formula or with the calculator dial if the flash unit has one. Turnthe lens’ aperture ring to that aperture.CAUTIONIt is recommended to use a Canon flash unit on this camera. Using a flash or flashaccessory of another make may cause the camera to work improperly or even possi-bly damage the camera itself. If you use a non-Canon flash. turn off the unit beforeYoU attach it to or remove it from the camera’s hot shoe. Before removing the flash,press the flash test button if it has one to discharge any power remaining in thecapacitor. These are merely precautions; following these steps will not necessarilyprevent the camera from being damaged by the flash unit.63