119 Reference informationAuto Aperture (AA) flash modeThe SU-800’s built-in sensor measures the flash illumination reflected from thesubject and controls the flash output in combination with data automaticallytransmitted from the camera and lens to the SU-800, including the ISO sensitivityvalue and exposure compensation value as well as the aperture and focal lengthof the lens.• Auto Aperture flash is available only when the SB-800 is used as a remote flash unit. (Awarning indicator appears if the SB-R200 or SB-600 receives an Auto Aperture (AA) flashmode signal.)• If the flash mode is set to Auto Aperture flash while a non-CPU lens is mounted, the AAmode display blinks as a warning, and the flash units will not fire.• For flash shooting distance range in the Auto Aperture flash mode, read the instructionmanual of your Speedlight. Notes on performing flash operation in the Auto Aperture flash modeWhen taking a distant subject, underexposure may occur even though thesubject is within the flash shooting distance range. Use of the TTL auto mode isrecommended with cameras compatible with TTL auto flash.
