Nikon 25446B D90 User's Manual - Page 218

❚❚ FV Lock This feature is used to lock flash output, preventing the flash level from changing between shots or while recomposing photographs. Flash output is adjusted automatically for any changes in ISO sensitivity or aperture. 1 Assign FV lock to the Fn button. Both the Fn and the AE-L/AF-L button can be used for FV lock. To use the Fn button as described below, select FV lock for Custom Setting f3 (Assign FUNC. button). To use the AE-L/AF-L button, choose FV lock for Custom Setting f4 (Assign AE-L/AF-L button, pg. 200). 2 Raise the flash. In i, k, n, and o modes, the flash will pop up automatically as required when the shutter-release button is pressed halfway. In P, S, A, and M modes, press the M button to raise the flash. 3 Focus. Position the subject in the center of the frame and press the shutter-release button halfway to focus. 4 L Lock flash level. After confirming that the flash-ready indicator (M) is displayed in the viewfinder, press the Fn button. The flash will emit a monitor preflash to determine the appropriate flash level. Flash output will be locked at this level and a FV lock icon (r) will appear in the viewfinder. M button Fn button 5 Recompose the photograph. 198