In photography, T (Time) is a shutter speed setting used for timed exposures that are longer than the standard numbered settings on a camera. When using T, the shutter opens when the release is pressed and remains open until the release is pressed again, allowing for precise control over very long exposures.
While T was once commonly used for night photography, light painting, and long-exposure techniques, it has largely been superseded by the B (Bulb) setting on modern cameras. Understanding T helps photographers appreciate historical camera designs and techniques, and it remains relevant for those using vintage or fully manual cameras.