Raw image of the Omega Nebula

This raw image, straight from EMMI, was used, together with many others, to produce the iconic colour photo of the Omega Nebula. The images taken with astronomical instruments are always monochromatic: the information on the colours is obtained by taking exposures through different glass filters. The thick black line cutting the field is the gap between the two CCD detectors in the camera. The centre of the brightest stars appears black, as the light saturated the detectors.