Here's how it works. In program, aperture-priority or shutter-priority auto exposuremode, metering system of the N4004sautomatically detects situations whichbenefit from balanced fill-flash andactivates the blinking viewfinder ready-lightindication to recommend you use thecamera's built-in flash or an accessoryNikon speedlight. For automatic balancedfill-flash , first set the camera in programauto exposure mode, then follow theseprocedures :•••••••••••••••••••••••••Check to make sure the subject iswithin proper flash shooting rangefor film speed in use. For details,see pages 40 and 41 .•••••••••••••••••••••••••••••••••1. Push flash lock-release buttons torelease built-in flash .2. Lightly press shutter release button toturn on the N4004s..,-...3. Confirm ready-light comes on, andshoot.39