When Is Lucky Imaging Better Than Adaptive Optics Techniques?
There is no doubt that Adaptive Optics techniques have been successful in certain areas. When the reference star is bright enough it has been possible to achieve very high Strehl ratios, and Adaptive Optics has been used extensively in the near infrared were we have not yet tried to apply Lucky Imaging techniques because of the lack of suitable detector systems. However there are a number of circumstances where the achievements of Lucky Imaging have exceeded those of Adaptive Optics. In order to understand the circumstances under which Lucky imaging excels we need to look at the way that Adaptive Optic systems generally work. Adaptive Optics works by breaking up the telescope aperture into cells of size of the order of r0 and detecting the reference star in each cell. This is most often done with the Shack Hartmann sensor: The images produced show an array of image is of a star, one from each of the lenslets in the Shack Hartmann sensor. A movie showing a typical image sequence can be
