A modelling light is a continuous light source positioned near an electronic flash, allowing photographers to preview how the light and shadows will fall on a subject before taking a photograph. It helps in composing and adjusting the lighting setup, ensuring the desired effect is achieved without multiple test exposures.
Modelling lights are commonly included with studio flash units, though some on-camera flashguns also feature a small strobe or bulb for this purpose. They are particularly useful in portrait, product, and still-life photography, where precise lighting control is essential for professional results.