Nikon D3300 Reference Manual page 351

AF-assist illuminator does not light:
• AF-assist illuminator does not light if AF-C is selected for autofocus
mode (0 74) or if continuous-servo autofocus is selected when the
camera is in AF-A mode. Choose AF-S. AF-assist is also not available
when f (3D-tracking (11 points)) is selected for AF-area mode; if
single-point or dynamic-area AF is selected, select center focus point
(0 78, 80).
• The camera is currently in live view or a movie is being recorded.
• Off is selected for Built-in AF-assist illuminator (0 229).
• The AF-assist illuminator can not be used in some shooting modes
(0 326).
• Illuminator has turned off automatically. Illuminator may become hot
with continued use; wait for it to cool down.
Image size can not be changed: An NEF (RAW) option is selected for image
quality (0 86).
Camera is slow to record photos:
• Depending on shooting conditions and memory card performance,
access lamp may light for up to about a minute after shooting ends in
continuous release mode.
• Turn noise reduction off (0 226).
Noise (bright spots, randomly-spaced bright pixels, fog, or lines) appear in photos:
• Choose lower ISO sensitivity or turn noise reduction on (0 226).
• Shutter speed is slower than 1 s: use noise reduction (0 226).
• Turn Active D-Lighting off to avoid heightening the effects of noise
(0 123).
No photo taken when remote control shutter-release button is pressed:
• Replace battery in remote control (0 308).
• Choose remote control release mode (0 97).
• Flash is charging (0 31).
• Time selected for Remote on duration (ML-L3) (0 247) has elapsed.
• Bright light is interfering with ML-L3 remote control.
Technical Notes 331