An ETC Source Four Lens Tube – 50º is a wide‑angle lens designed for very short throw distances where broad, even light coverage is needed. The 50º beam spreads light across a large area, making it ideal for stage washes, front light from close positions, and filling in areas where fixtures are mounted near the stage. It provides smooth, consistent coverage while still allowing basic shutter control for shaping the light as needed. This lens tube installs directly into compatible Source Four ellipsoidal fixtures and is commonly used in theaters, studios, and houses of worship where wide coverage is more important than tight beam focus.