Comparing AO techniques

Central parts of the globular cluster Omega Centauri, as seen using different adaptive optics techniques. The upper image is a reproduction of ESO Press Photo eso0719, with the guide stars used for the MCAO correction identified with a cross. A box shows a 14 arcsec area that is then observed while applying different or no AO corrections, as shown in the bottom images. From left to right : No Adaptive Optics, Single Conjugate and Multi-Conjugate Adaptive Optics corrections. SCAO has almost no effect in sharpening the star images while the improvement provided by MCAO is remarkable.