Vertical illuminance is measured on a vertical surface such as a shelf face, wall, board or face plane.
Vertical illuminance is illuminance on a vertical plane. It helps separate shelf, wall, face, board or display visibility from horizontal floor or desk lux.
Technical meaning
Vertical illuminance describes light arriving on an upright plane, not on a horizontal desk, bench or floor.
It can matter for warehouse labels, retail displays, noticeboards, faces, mirrors, wall signs and other surfaces people view directly.
Vertical illuminance on a viewed faceVertical illuminance belongs to the face being viewed, so floor lux cannot stand in for that record.
Calculation use
A measured vertical lux value should be recorded with the surface, height, viewing direction and operating condition.
Horizontal lumen or room estimates should not be used as proof that a vertical face is adequately lit.
Not the same as
Vertical illuminance is not the same as average room lux.
A vertical reading is not a formal workplace or public-space assessment unless the applicable method and sampling note are defined.
Australian context
Australian office, warehouse, retail and public-facility notes should name vertical surfaces when labels, faces, boards or display walls are part of the visual task.
Examples
Example
Value
Planning note
Warehouse shelf face
vertical lux reading
Useful where labels are read on racking rather than the floor.
Classroom board
board plane
Should not be replaced by a desk-plane reading.
Mirror area
face plane
Needs glare and fitting position notes as well as the number.