Many objects that move during a process are illuminated with a very bright line LED unit and inspected with a line camera. Depending on the application, a narrow, focused, and therefore very bright light strip can be produced by various diffusers and lenses, or a diffuse light with wider emission can be created for use as transmitted light. The advantages of line lighting are high light output, compact, robust design, and high efficiency. Line lighting is available with different cooling options.