Polarimetric frames of the two fields for 1ES 1959+650 (top), and HB89 2201+044 (bottom), observed in the R band. In both cases, the white and green circles indicate the locations of the blazar and field stars for the ordinary and extraordinary images, respectively, prior to the virtual masking. Labeled with 1 are the blazars, and with numbers larger than one are the field stars whose fluxes were measured. The field of view is 9×9 arcmin, east is up and north is to the right.