Nikon D3300 Reference Manual page 143

2
Choose an option.
Highlight On or Off and
press J (0 345).
D
Active D-Lighting
Noise (randomly-spaced bright pixels, fog, or lines) may appear in
photographs taken with Active D-Lighting. Uneven shading may be
visible with some subjects. Active D-Lighting can not be used at an ISO
sensitivity of Hi 1.
A
"Active D-Lighting" Versus "D-Lighting"
Active D-Lighting adjusts exposure before shooting to optimize the
dynamic range, while the D-Lighting option in the retouch menu
(0 266) brightens shadows in images after shooting.
P, S, A, and M Modes 123