Nikon D3200 Reference Manual page 35

Select On to reduce noise (bright spots, randomly-spaced bright
pixels, lines, or fog). Noise reduction takes effect at all ISO
sensitivities, but is most noticeable at higher values. The time
required for processing at shutter speeds slower than about I s
or when the camera's internal temperature is elevated and ISO
sensitivity is high roughly doubles; during processing,
uoo nr" will flash in the viewfinder and photographs can not
be taken. Noise reduction will not be performed if the camera is
turned off before processing is complete.
If Off is selected, noise reduction will only be performed at high ISO sensitivities; the
amount of noise reduction is less than that performed when On is selected.
Choose whether the built-in AF-assist illuminator lights to assist
the focus operation when lighting is poor.
AF-assistilluminator
Option Description
The AF-assist illuminator lights when lighting is poor (viewfinder photography
only). AF-assist illumination is only available when both of the following
conditions are met:
On I. AF-S is selected for focus mode (_ 35) or single-servo autofocus is selected
when the viewfinder is used in AF-A mode.
2. ["3 (Auto-area AF) is chosen for AF-area mode > Viewfinder (_ 38, 39), or
an option other than ["] (Auto-area AF) is chosen and the center focus point is
selected.
The AF-assistilluminator does not light to assist the focus operation. The camera
Off
may not be able to focus using autofocus when lighting is poor.
See Also
See page 37 for information on using the AF-assist illuminator. Information on the shooting
modes in which AF-assist is available may be found on page 187. See page 171 for
restrictions on the lenses that can be used with AF assist.
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