An 850u SCUBA image of DR21 with superimposed polarization vectors. The polarization is about 3% and the magnetic field direction is perpendicular to the vectors. The field direction is parallel to the main outflow axis and almost perpendicular to the main dust ridge. These data were acquired in 30 minutes. (Courtesy J. Greaves, W. Holland, A.G. Murray and R.Nartallo)