Nikon 13187 User Guide (en)

Noise (bright spots, randomly-spaced bright pixels, fog, or lines) appear in photos
• Choose lower ISO sensitivity or use high ISO noise reduction (
• Shutter speed is slower than 1 s: use long exposure noise reduction (
• Turn Active D-Lighting off to avoid heightening the effects of noise (
AF-assist illuminator does not light
• AF-assist lamp does not light if AF-C is selected for autofocus mode (
0 97) or if continuous-
servo autofocus is selected when the camera is in AF-A mode. Choose AF-S. If an option other 
than auto-area AF is selected for AF-area mode, select center focus point (
• The camera is currently in live view or a movie is being recorded.
• Off selected for Custom Setting a7 (Built-in AF-assist illuminator) (
• Illuminator has turned off automatically. Illuminator may become hot with continued use; 
wait for lamp to cool down.
Smudges appear in photographs
: Clean front and rear lens elements. If problem persists, perform 
image sensor cleaning (
Sound is not recorded with movies
Microphone off is selected for Movie settings Microphone.
The brightness of the image in the monitor differs from the exposure of photographs taken in live view
• Center-weighted or spot metering is selected (
• The camera is in mode M.
• The subject is too bright or too dark.
• Active D-Lighting is in effect (
• The photograph is a long time-exposure (
• The flash is used (
Flicker or banding appears during live view or movie recording
: Choose an option for Flicker reduction 
that matches the frequency of the local AC power supply (
Bright bands appear during live view or movie recording
: A flashing sign, flash, or other light source with 
brief duration was used during live view or movie recording.
Menu item can not be selected
: Some options are not available in all modes.