lightrails

Lightrails are a photographic effect in which the movement of light sources is recorded as elongated trails within an image, usually produced by long exposure imaging. The result can reveal dynamic urban scenes, celestial motion, or deliberate light drawing within a scene.

To create lightrails, a camera is typically mounted on a stable tripod and operated with a long exposure, or by stacking multiple shorter exposures. Exposure times can range from several seconds for traffic trails to many minutes or hours for star trails. Lower ISO and careful aperture choices help reduce noise and control brightness, while remote shutters or intervalometers help minimize camera shake.

Common types of lightrails include star trails, which form circular or arc patterns as the sky rotates; vehicle or traffic trails, which appear as continuous lines along roads; meteor and fireworks trails, which produce brief streaks; and light painting, where a moving light source is intentionally illuminated within the frame during the exposure.

Techniques vary: a single long exposure versus multiple-frame stacking. Stacking several exposures can reduce sensor noise and allow longer total recording time while maintaining exposure quality. Post-processing often involves aligning frames, blending light trails, and removing unwanted noise or bright distractions.

Applications range from artistic and urban night photography to observational studies of movement patterns in traffic. Lightrails require dark skies or controlled lighting, and successful results depend on planning, weather, and equipment capable of long, stable exposures.