The effective working distance of a camera flash is directly related to ISO film speed you use and the lens aperture selected by the camera. Riva and KONICA MINOLTA ZOOM CAMERAS: The flash output of Konica Minolta compact cameras is always at full power. Correct flash exposure is obtained by adjusting the aperture to the proper one for the camera-to-subject distance as measured by the camera’s autofocus system. When used at the widest zoom setting, the widest lens aperture is available and the working distance is the greatest. As the lens is zoomed out, the size of the maximum available aperture becomes increasingly smaller and the effective working distance of the flash becomes less and less. Using faster films such as ISO 400, ISO 800 or higher will help improve the flash range of your camera. Be sure to consult your camera instruction manual for the proper flash range for your camera. SLR CAMERAS LIKE Dynax AND X-700: The power of built-in or accessory flash is expressed as a Guide Number for ISO 100 film when the camera is used with a 50mm f/1.4 lens. If faster film is used, i.e., ISO 200, 400, 800, the guide number and thus working distance of the flash is increased. As higher aperture numbers are selected, (i.e., f/2.8, f/5.6, f/8), the working distance is reduced. It is recommendable to use faster film when you expect to shoot with higher apertures or subject at greater distances. Be sure to consult your owner’s manual for the proper flash range for your camera. The flash systems of the Dynax 5, Dynax 7 and Dynax 9 offer improved flash exposure control when used with HS-type flash units by detecting and adjusting flash brightness for subject reflectivity. The Dynax 5 and Dynax 7 offer additional control with new Series D lenses and the 3600HS D and 5600HS D flash units. See product information for more information