78 Menu Guide/Custom Settings14: Built-in Flash (P, S, A, and M Modes Only)Choose a flash control mode for the built-in flash or the optionalSB-400 Speedlight.TTL (default): Flash output is adjusted automatically in response toshooting conditions.Manual: The flash fires at the level selected in the menu shown atright. At full power, the built-in flash has a Guide Number of 18/59(ISO 200, m/ft., 20°C /68 °F).A icon flashes in the viewfinder and shooting information dis-play when Manual is selected.The Optional SB-400 SpeedlightWhen an optional SB-400 Speedlight is attached, Custom Setting 14 isused to choose the flash control mode for the SB-400 and the namechanges to Optional Speedlight.15: Auto off TimersChoose how long the monitor and exposure meters ( 14)remain on when no operations are performed. Choose a shorterauto off delay for longer battery life.Note that the shooting information display turns off automatically when the exposuremeters turn off.Using an AC AdapterRegardless of the setting chosen, the monitor and exposure meters do not turn off automaticallywhen the camera is powered by an optional EH-5 AC adapter and EP-5 AC adapter connector ( 103).Option DescriptionShort Monitor and exposure meters remain on for 4s. When Image review is on, pictures aredisplayed in monitor for 4s after shooting ( 75).Normal(default)Monitor and exposure meters remain on for 8s. When Image review is on, pictures aredisplayed in monitor for 4s after shooting ( 75).Long Monitor remains on for 20s; exposure meters remain on for 1minute. When Imagereview is on, pictures are displayed in monitor for 20s after shooting ( 75).Custom Choose monitor off delay and image review time from 4s, 8s, 20s, 1minute, and10minutes. Choose auto meter-off delay from 4s, 8s, 20s, 1minute, or 30minutes.