Only D-Flashes (5600HS(D), 3600HS(D), 2500D) are fully compatible (TTL/ADI-metering). It is possible to use some older flashes in manual mode. For older flashes: Flash and camera should be switched to manual mode. There is no flash metering. For D-7 Series: If the monitor is too dark, press PASM-Button and i+ button simultaneously in M-mode. For A-Series: See shortcuts in Setup mode for automatic monitor amplification in M-mode. See flash compatibility on this web page ("compatibility information")