Stroboskop

A stroboscope, or Stroboskop in German, is an instrument that produces brief, periodic light flashes to illuminate a moving object. By adjusting the flash rate, the observer can see the object as frozen in place, slowed, or moving in apparent slow motion. This optical effect arises from sampling the scene with very short light pulses, while the eye retains image information for a fraction of a second.

In use, the flash frequency is set close to a multiple or submultiple of the object's motion, causing apparent stasis at a fixed position or aliasing that makes motion appear reversed or slowed. Modern instruments use LEDs or gas/ xenon flash lamps and can be hand‑held or mounted. Some stroboscopes are coupled to a tachometer so the flash rate tracks a rotating part's speed for direct measurement.

Applications include industrial inspection of rotating machinery, gears, conveyors, and cams; measurement and alignment tasks; vibration analysis; theatrical lighting and photography for creating motion effects; and demonstrations of oscillatory phenomena in education. Stroboscopes are also used in science laboratories and manufacturing to study cyclical motion and to synchronize processes.

Safety and limitations: bright pulses can cause discomfort and may trigger seizures in photosensitive individuals; excessive use can produce misleading perceptions if the user misinterprets aliasing. Flicker is more noticeable at certain frequencies and exposure levels; proper dimming, filtering, and appropriate duty cycles help mitigate visual fatigue and misinterpretation.