A local peak in illuminance or luminance: the bright center of a narrow beam on a wall, the visible dot of an LED through a thin diffuser, or the reflection of a source in a glossy surface. Hot spots draw the eye where the designer did not intend and create uneven appearance. Common fixes include wider or softer optics, diffusion or spread lenses, re-aiming, or adding distance between source and surface.
There's a hot spot on the top of the reception desk from that pinhole, add a spread lens and it'll even out.
Also heard as
- hotspot
- bright spot
Related terms
Beam angle
The angle across a light's beam at which intensity has fallen to 50 percent of its center value.
Tape light
Flexible LED strip on an adhesive-backed reel, cut to length and used in coves, shelves and under cabinets.
Uniformity
How evenly light is spread over an area, expressed as a ratio such as minimum to average or maximum to minimum.
Glare
Visual discomfort or loss of visibility caused by excessive brightness or contrast in the field of view.
Same word, different worlds
Localized area of active corrosion on a pipeline, or the targeted anodes installed to protect just that spot.
Refractories & Furnace LiningsArea of a vessel or kiln shell running hotter than normal because the lining behind it is thin or gone.
Nuclear Safety & Radiation ProtectionA small spot on piping or equipment with a much higher dose rate than its surroundings.
Photonics & LasersA small region of a beam with much higher intensity than the rest, a common cause of optic damage.