Pentax 645 645 Manual - Page 48

UTILIZING PENTAX DEDICATED FLASH UNITS The compatible combination of the Pentax 645 and one of the Pentax dedicated auto flash units will allow convenient use as indicated in the table below. When using the AF400T, connect the unit to the hotshoe contact of the camera via the 4P synch cord B. Do not attempt to couple the cord to the X-synch socket, othervyise, the camera's flash coupling capability will fail to function. A dedicated flash unit, when used with the Pentax 645, may not fire if the subject is too bright for flash photography. FLASH COUPLING FUNCTIONS OF THE PENTAX 645 Upon completion of charging S will be displayed in the external LCD display window and ..z on the viewfinder LED display. With any photographic mode, the shutter speed is automatically switched to the synchronized speed of x setting 0160 sec.), upon completion of charging. (When using an ordinary flash unit other than the dedicated TTL auto flash units, the aperture ring should be set to an appropriate f/stop other than the "A" positioning) If the aperture ring of the A lens is set to the "A" position, the 645's flash coupling function automatically switches the aperture to the necessary f/stop to enable TTL auto flash control. Whenever the auto flash unit has emitted an appropriate luminosity, a visual marking I ..r ) will light up or blink in the viewfinder, immediately after flash discharge. With the use of a dedicated TTL auto flash unit, the flash luminosity may be automatically controlled by the measuring of the light volume reflected off the film plane while photographing. When the Metered manual mode is used, synchronized flash photography is possible at shutter speed at 1160 sec or lower. indicates Pentax dedicated TTL flashes 46 AF400T, AF280T AF200T, AF080C AF260Sit , AF200SA AF160Sa , AF240Z