Filters can also be used to partially compensate for the effects of light pollution by blocking out unwanted light.

Light trespass occurs when unwanted light enters one's property, for instance, by shining over a neighbor's fence.

The weather turned cold, and a black tarp that had covered the tank, blocking out unwanted light, tore.

They are too bright, too sensitive and often badly angled, sending unwanted light into neighbouring windows and the night sky, say critics.

This allows for a sharper image by blocking out unwanted light.

Either way, the instrument design must take into account scattering and diffraction to make sure that as little unwanted light as possible reaches the final detector.

New Jersey astronomers are often threatened by development and the unwanted light it brings.

But her plastic surgeon kept her wounds camouflaged by one type of dressing or another designed to screen out unwanted light while letting in healing air.

Hubble's structure includes a heavy tube which keeps out unwanted light, especially light reflected from our own planet.

Double reflections and inter-reflections can cause the stripe pattern to be overlaid with unwanted light, entirely eliminating the chance for proper detection.