Starfinder: a code for crowded stellar fields analysis

Starfinder is an IDL code for the deep analysis of stellar fields, designed for well-sampled images with high and low Strehl factor. The Point Spread Function (PSF) for the analysis is extracted directly from the CCD frame, to take into account the actual structure of the instrumental response and the atmospheric effects. An important feature is represented by the possibility to measure the anisoplanatic effect in wide-field Adaptive Optics (AO) observations and exploit this knowledge to improve the analysis of the observed field. A description of the method and applications to real AO data are presented.