The control of light emitted at high angles, especially above horizontal. A full cutoff outdoor luminaire emits no light at or above 90 degrees from nadir and limits light near the horizon; ordinances often use the looser term fully shielded, which only bars light at or above horizontal. Indoors, the cutoff angle, measured from straight down, and its complement the shielding angle, measured from horizontal, describe where the bright source drops out of view. Outdoors, BUG ratings cover the same ground in more detail.
Ordinance wants full cutoff on every pole, so the decorative globes are out unless they come with an internal shield.
Related terms
BUG rating
An outdoor luminaire rating for backlight, uplight and glare, each scored 0 to 5, used in light pollution ordinances.
Light trespass
Unwanted light that crosses a property line or falls where it is not needed, such as into a neighbor's window.
Glare
Visual discomfort or loss of visibility caused by excessive brightness or contrast in the field of view.
Spill
Light that falls outside the area it is aimed at, onto walls, ceilings, audiences or neighbors.