There is a choice of two apertures for automatic flash photography. To select an aperture set the Aperture/MANU selection switch to the upper or middle position; the aperture value will appear in the Aperture/MANU window. The aperture will change depending on the setting of the ASA film speed. When ASA 100 film is used for instance, the upper position is f/2.8 and the middle is f/5.6

When the Aperture/MANU selection switch is set on the lowest position "MANU" appears in the window. As this indicates manual flash photography, automatic flash photography is impossible on this setting.

• In automatic flash photography, if the ASA film speed is set between graduations, such as 64 or 80, the aperture value indicated is between click-stops on the aperture ring. In the case of the Av-1 or At-1, set the lens' aperture ring to the click-stop on the brighter side.