VISTA main mirror recoated

The VISTA primary mirror in the vacuum chamber after recoating, just before being installed in the telescope. While the VLT´s mirrors are covered by aluminum, the VISTA mirror is coated with silver, because this element has a better reflectivity in the infrared. The VISTA primary mirror is 4.1 metres in diameter and is the most highly curved of its size. The extremely high curvature reduces the focal length, making the structure of the telescope extremely compact. VISTA can map large areas of the sky quickly and deeply. Unlike the other telescopes at Paranal Observatory, VISTA has its own coating plant installed in the same telescope building.